Rebuilding

* Quadra-jet Carburetor

* Pulling Engine
* Rebuilding Engine
* Installing Engine

* Rebuilding Steering Box

* Pulling Transmission
* Rebuilding Transmission
* Installing Transmission

* Differentials

Submit corrections and additions to this information to The Olds FAQ Compiler.



Quadra-jet Carburetor

When it comes to loosening that darn, blasted, made from putty and welded in place fuel line, flare wrenches are not an end all - don't get discouraged. They flex and bend and usually you're lucky if you're the first mechanic to get your mitts on it. Before using your vise-grip on the nut, try using it on the flare wrench, to prevent the opening of the flare nut wrench from flexing. This might be enough the loosen the nut. Another alternative are crows feet flare wrenches.

Vice grips on a tubing line nut = instant destruction. Fine if you want to replace the nut - but be careful, the vise pressure turns the nut into an oblong, rather than a concentric circle, and if this happens to be turning into an aluminum carb inlet, good luck sealing your inlet. Be patient, a tubing (or flare nut wrench) is all you should use. File the nut points, if they are not sharp, and sides flat, and try putting some electrical tape around the nut to make the wrench tighter. Be sure the other nut is held by a wrench also - sometimes a quick snap with a plastic tipped hammer on the wrench will break it loose. We all use vice grips as last resort sometimes, and this usually results in more work.


Quadrajets - most stock 4-barrel Olds's come equipped with one, yet most of us are reluctant to touch them, even when it comes to a simple rebuild. Why? Mostly because it is the least talked about, least understood carburetor mounted on cars. 4M, 4MC, 4MV, M4M; all these silly numbers, lots of levers, vacuum lines, and other gizmos all contribute to make that thing look overly complicated and impenetrable.

"Quadrabog", "Quadraslob", "Quadrajunk"; these and other names which I can't mention, all are used to describe what is actually a good performance/mileage carb. Most of the Q-Jet's bad reputation has resulted from the hot rodder's "bolt on" approach and the availability of the popular Holley carb.

So if the Q-Jet can be made into a good performance carb, how do we start? Well, we first must understand a little about how they are different, and then we can use this knowledge to extract the excellent performance and driveability that the carb is capable of.

The two babies up here [2 carb graphics at top of page] are 4MV (on left) and 4MC (on right). The nomenclature only indicates the choke configuration. The 4M has a manual choke, the 4MC has a choke on the carb ('70 and later Olds) and the 4MV has teh choke housing onthe intake ('66-69). The M4M is the emissions Q-Jet introduced in 1975, which has had certain adjustability added in while some of the off-idle power transition is taken out. It can be made to deliver power, but the older models will do a better job.

Basically, the carb is almost totally vacuum controlled, proper setting of the signalling devices is ABSOLUTELY NECESSARY to ensure it will work correctly. This should be done BEFORE ANY CHANGES ARE MADE! If you are going to rebuild the carb, do this before you set it up.

For the rest of this article, we will assume that you are in the process of rebuilding the carb as much of what you can do is done with the carb apart. Buy a quality rebuilding kit and clean everything thoroughly after disassembling the entire carb. Lay all the pieces out and familarize yourself with all of them. I suggest that you have the Olds Chassis Service Manual for your year carb or an aftermarket book on Quadrajet rebuilding. [Rebuild kits usually have excellent diagrams included.]

We'll go through the rebuilding steps while we explain how the Q-Jet works. This way, you'll learn how to fix it as well as what affects what. OK, let's get started.

With the carb disassembled, we have three major pieces: the base, the float bowl, and the air horn (top of carb). Put aside the base and the air horn for now and grab the float bowl. Most of what we are going to do is going to happen in this baby, so start by turning it upside-down and looking at the bottom. [Graphic of upturned float bowl]

FLOAT BOWL TURNED OVER: Arrows indicate main fuel casting wells. These MUST NOT LEAK [famous leaking wells] as they will draw raw fuel into the manifold and ruin performance and idle.

You'll see four bumps sitcking up. These are the casting wells for the main fuel wells. These are capped when the carb is make, but after a while, they tend to crack and leak. Mix up some epoxy and coat the tops of these bumps, covering the pressed in plugs. Set aside the float bowl and let the epoxy dry.

Pick up the carb base and run a straight edge over it [both surfaces mating to manifold and float bowl]. If it is not straight, throw it away. Go junque yarde jaunting and aquire a bunch of used Q-Jets (I should have told you this earlier) for similar years [good luck] ('66-67), ('68-69), ('70-72), ('73-74), ('75-80). Check for straightness and also check to see if the throttle butterflies open without sticking or close properly. The secondaries should open to about 5 degrees of vertical, no more, no less. Put the base aside and pick up the now dried float bowl.

Turn the bowl right-side-up and peer into hole "B" in the picture at the top to the page. This is the power piston bore. If you look real good you'll see a little spring in there that you didn't take out when you TOTALLY disassembled the carb. You're forgiven, but use needle-nosed pliers and remove it. This baby controls the idle/of idle fuel mix, and it is not happy if you have changed the cam to a long duration type. This is especially true for 350/403s. Guys who have went the W-31 route, TAKE NOTICE! [Graphic of carb w/air horn removed viewed from top]

There are many power piston springs to choose from, but some of the favorites I'll suggest are:

PP Spring Notes
7037851 72 W-30 very soft (lean)
7029922 69 W-31 soft/medium
7011967 69 W-30 medium
7036019 70 W-30 auto stiff (rich)

Install the leanest first, run the car, and then try the next, and so on. Stay as lean as possible here as these springs affect idle more than power.

Next, we'll work with the primary metering rods. These are the skinny littly guys which are stuck in the primary metering jets. [Graphic of primary & secondary metering rods]



They're attached to the power piston (which fits into the hole you dropped the spring in). No matter what set you have, go out and get the following:

Power Piston Notes
7034840 stamped 40B (richest)
7034842 stamped 42B
7034844 stamped 44B (most Oldsmobiles)
7034846 stamped 46B (leanest)




Again, start with your present rod and move richer to see if performance improves. If the car is "flat" on acceleration try leaner, then richer.



The next step is the primary jet. These are the screw in babies in hole "D". [see top view graphic w/air horn removed]. Here's the ones to have in your tool crib:

Primary Jet Notes
7031969 stamped 69 (leanest) mostly in 350s
7031970 stamped 70 1970 350 & 455
7031971 stamped 71 1966-68 all
7031972 stamped 72 1968-69 400 SMT
7031973 stamped 73
7031974 stamped 74 1968-69 W-31
7031955 stamped 75 1969-69 400 W-30/W-32






After getting the best results with the rods, start with one step leaner jet (unless you already have a 69) and work up.






Obiously, we've been combining rebuilding with tuning in this article. In reality you'd be rebuilding to stock specs first, trying the carb, then going back inside and making changes. This would hold true unless you had changed to a radical cam at the same time. Then you should have replaced the power piston spring with a leaner unit. This is because the power piston is controlled by vacuum and big cams make less vacuum, hence a softer spring. The steps from now on SHOULD BE MADE NO MATTER WHAT.

First, the fuel inlet seat ("A" on the top view of the carb) should be replaced with GM part 7035140, which should be used with all stock/modified cars using GM mechanical fuel pumps. With any fuel delivery system with over 5 psi, use GM assembly 7035130. Stay away from the seat supplied wiht most rebuilding kits unless rebuilding a totally stock carb as they are of questionable quality and do not deliver sufficient fuel.

Set our float to 9/32" and ensure that the fuel level does not climb too high and slosh into the power valve hole and overly enrich your mixture. [Graphic of front upper view of carb w/air horn removed]

FLOAT BOWL PIVOT PIN - Held in place by the air horn. Spread it slightly so that the floar/needle can't climb out under high fuel pressure situations.

Adjust the float, set it and the needle in place, then insert the primary needles/power piston in place. BE CAREFUL TO INSERT THE NEEDLES IN THE JETS AS YOU INSERT THE PISTON OR YOU WILL BEND THEM! Drop in the float chamber baffle as it keeps the fuel in the float well and has no affect on the amount of fuel in the chamber!

Assemble the air horn and the fuel float bowl using the proper gasket. There are quite a few different ones so make sure the one you use has the same holes and the same configuration as your carburetor. This operation is usually a pain as the accelerator pump lever arm link requires the arm to be inserted into it as you are trying to tilt the air horn onto the float bowl in 1968 and later carbs. The '67 and '66 units use a link wich is inserted afterwards and has a pin to hold it in place. Scrounge the junk yards for this piece and use it. CAUTION: some links are of different length, be sure to use the one with the same length.

For proper accelerator pump discharge (Olds engines) always use the inner lever arm position. Screw down the carb air horn with the two center screws. STOP HERE and turn the carb over. Check the gasket used between the float bowl and the base as you did for the air horn/float bowl unit. Place it on the base and mate the base to the float bowl. You will use either two screws or three, depending on the year and type of carb you have. I suggest you utilize small lock washers on these screws. Use ones which will fit in the screw well. This is a better method than Loc-Tite. These screws have a nasty habit of loosening up and causing vacuum leaks.

Now turn the carb over, install the rest of the screws and turn them in according to the sequence in the Chassis Service Manual. [Graphic of 7 secondary metering rods ranging from thick(lean) to thin (rich)]

Now it's time for the secondary metering rods. We are able to control fuel metering by both the rod size and the hanger. Let's discuss rod size first:

Secondary Rod Notes
7033830 stamped AY (leanest) '73 and later 350
7033658 stamped AT '70 442 SMT & 350
7033655 stamped AU '66-69 big block, W-30 & W-31
7046004 stamped DA
7033549 stamped AX '71 Toro
17056618 stamped DS (richest) Buick V-6 Turbo



Most carbs can be enriched one rod with no problem. All W-Machines should go right to the "AX" rod. The "DS" rod should only be used for racing.





More adjustment of the secondary circuit can be made with the rod hanger. These hangers are coded A, B, C, etc., in 0.005" changes in height, with "A" being the highest and "Z" being the lowest. Therefore, an "A" hanger will pull the rods out sooner and higher than a "Z". These are no longer available except for the "V" hanger, so off you go to the junk yard.

OK, now that you've acquired all these pieces, rebuilt the carb, installed bseline rods, jets, and the like, you are ready for final testing. Adjust all the fast idle, dash pot, vacuum break, etc. as specified in the chassis service manual [or the detailed kit instructions]. Now you can bolt the carb to the manifold. I suggest that a relatively SOFT gasket be used. Fel-Pro and Mr. Gasket offer a thicker unit with a composition which seems to hold up well. If this gasket gets too hard from heat (a common problem with aluminum manifolds), it will leak and ruin your idle/tuning. Remember, a Q-Jet is vacuum controlled, so...

I suggest that you run an in-line fuel filter of very high fuel flow capacity. A Fram GF-15 is what I use. If you are a stickler for stock fuel line appearance, put it in-line where the line comes out of the front of the K-Frame and attaches to the fuel pump. The reason for the in-line filter is that we want to remove the filter in the nose of the carb. This allows us to almost double the fuel available to the carb during wide-open throttle situations.

Our two final adjustments are critical. The first is the secondary air valve spring "wrap". This little guy determines when the secondaries open. While I will give you the base-line, you'll have to find the optimum by testing (PEDAL TO THE METAL!). [Graphic of secondary air valve spring & lock]

The allen head set screw (A) must be loosened first. When there is no tension on the air valve butterflies, the spring tension is set with the screw (B).

Loosen the allen head screw until you see the tension go completely out of the butterfly. Then insert a small screw driver into the screw (B). Slowly turn the screw clock-wise, while tapping on the carb lightly until the butterfly rotates up and contacts the air horn. Turn the screw another ¼ turn. Hold the screw in this position while tightening the allen head screw. (Wouldn't it be nice to have a third hand now?)

This is your base-line setting. Less tension will opent he valve sooner; more will open it later. The test should go like this:

  1. Disconnect the vacuum hose from the choke diaphram and plug the hose ONLY.
  2. Go out and try a Wide Open Throttle acceleration. (The fun part!) Decrease the wrap (loosen) until a loss of performance is noted by bog.
  3. Connect the diaphram and see if the bog goes away. If not, tighten in 1/8 turns until it does.
  4. Once that is as good as possible, go one step richer with yor secondary rods and see what happens. If you run betteer, go a step richer - if not, check the wrap again. If there is no improvement, go back to the old rods.
  5. When you have the old rods back in, go two steps towards "A" (i.e. from a J to H) with the rod hanger. Repeat the procedure.
  6. After you get the best results, check your plugs to see if you are too lean. If so, go up two numbers in your primary jets and one step in your primary rods.
  7. If you are still too lean, consult below.

The following racing mods should only be done for a car which exhibits overly lean conditions @ WOT or is highly modified and is a RACE ONLY CAR.

Mike Jones Carburetion, 7602 Talbert, Hunnington Beache, CA 92647 sells accelerator pump pistons with differing length shafts These allow more or less of a shot of gas. He also offers a ligher return spring and a stiffer shaft spring. Mixing/matching can allow more precise metering. The shaft length also allows a different point at which fuel delivery starts.

The air valve dashpot can be modified by drilling out the orfice from 0.025" to 0.035". The rear fuel bowl vent can be plugged to prevent fuel sloshing. '75 and later Q-Jets ought to be enlarged to 0.010".

The passage between the main fuel well and the two secondary wells can be enlarged to 0.050", which will allow them to fill quicker.

Here are some DON'TS!

Don't remove the baffles from the secondary bores. They ensure proper fuel mixture/atomization.

Don't remove the plastic float chamber baffle as it helps to direct the fuel into the chamber as it sits above the fuel level.

Don't try to set the idle without holding the hot idle compensator tang back on the back of the carb.

Follow these tips and your Quadra-Jet will perform with the best of them. Because it is mostly vacuum controlled, it does require a bit more setting up than a Holley, but when properly dialed-in, it can deliver better around town driveability and real Go Power when the hammer is dropped.

Try these tuning/adjustment tips. They have worked very well for me. I only have stock cars and so haven't tried the highly modified stuff.

I get as many old Quadra-Jets as I can from the junque yarde at $3-$5 each. This is a source of parts. Most all of the carbs are interchangeable as well as their 3 main parts. I believe base plates can be salvaged if necessary by twisting them in your hands until they pass the straightness test.

[ Thanks to Bill Culp for this information ]


Differentials

[ Notice: ]Please refer to the Differential Rebuilding section!


Pulling Engine

Precautions

[ Thanks to Charly Buehner, Bob Barry, Joe Padavano, Mick Gillespie, Dave Wyatt, Frank Boerger, Bill Culp, Andrew Green, Chris Ruper, Jason Labay, Scott Mullen for this information. ]

Getting Down to Business


Pulling Engine/Transmission

There's two ways you can do the removal. Some people (such as myself) remove the transmission from beneath the car and then pull the engine out the hood opening seperately. Others prefer to remove the engine/transmission as a pair - without unbolting the two. However you do it, the torque converter stays on the transmission - if you tried to pull the converter out of the transmission you'd have fluid everywhere. Also the transmission will have to come out unless you're going to put something under the front of the transmission to support it, because without the engine in the car the transmission has nothing on the front to hold it up. However, no matter what you do, if you ARE going to unbolt the engine and transmission, FIRST, before you unbolt the bellhousing, unbolt the 3 torque converter bolts - DON'T FORGET THESE!! I had a momentary memory lapse in this regard when doing my disassembly and had fluid all over my work area.

One more thing - if you are going to remove the transmission from beneath the car and then remove the engine, support the engine with a "cherry-picker" or an engine hoist before you remove the transmission because the engine may not stay level on the engine mounts without the transmission - it may rock backwards into the firewall and the distributor will be the first thing to contact the firewall - probably bending it or breaking it if it hits it hard enough.

If you do the job singlehandedly, it helps to tie a rope or a small chain to the front of the motor and then loosely wrap it around the back part of the hoist. The rope keeps the motor from swinging around too much while it's dangling up in the air.

A big floor jack with a pad of plywood under the transmission pan is handy so that you can lower or raise the tail to just the right place while you're sliding the engine/tranny forward.

Toronado Engine Removal Tips and Tricks

Well, being in a salvage yard (mud, etc.), I was unable to get under the car or raise it to any significant degree. I discovered that I would be unable to get the engine out alone, so I disconnected the front engine mount, rear trans mount, exhaust, and the 12-point bolts holding the CV shafts to the axle (I was lucky I brought a 7/16 12-point socket). I then had the fork truck lift the engine/transaxle out and lay it on the ground. At this point I rolled the assembly over (broke the oil fill tube and the dip stick tube off) and removed the flywheel cover and the torque converter bolts. I then rolled everything back over and removed the bellhousing bolts which allowed the engine to come loose (whew!). Yes people walked by and laughed, but I didn't care. I WANTED THAT 455.

Don't forget the flexplate->torque converter bolts; the dust shield for this is a rather complex, two-piece hinged metal affair, and one of the bolts holding this dust shield on is hidden on the driver's side, under where the exhaust manifold would be (you'll have to remove the exhaust manifold to access it. Without removing the dust cover, and the torque converter bolts, that engine isn't going anywhere without that transmission attached.

Yes. The trick is to loosen the rear transmission mount bolts with a floor jack supporting the rear of the tranny; angle the transmission backwards slightly, and angle the engine forward slightly, to get the flexplate to clear the bellhousing. Once that is clear, you can wiggle her out of there. Otherwise the axle might get caught on the oil pan.

Yes, if you unbolt (12 point 7/16" head bolts) the halfshafts and the tranny mounts, that whole assembly will be free to lift. Good luck finding mounting points that will allow you to balance that whole assembly; not that you can't- I'm just wishing you luck in doing so... Watch out for attaching the lifting chain too low; the whole assembly could swivel 180' over, which wouldn't be pretty, and could be very dangerous. Use at least three solid lifting points if you go that route.

Better than removing the halfshafts, try unbolting the differential from the transmission case. The problem is the right-front intermediate shaft, which the oil pan is hitting; unbolting the differential case might allow you enough play to get the engine out of there. The transmission and final drive are actually two separate pieces, though they are directly bolted together, so it's not simply a one-piece transaxle.

It can be done; it took me some time pulling my 455 from a '68 Toro, but I eventually wiggled it out of there.

[ Thanks to Dave Wyatt, Frank Boerger, Bob Barry, Bill Culp, Andrew Green, Charley Buehner, Jason Labay, Joe Padavano, Scott Mullen, Steve, Glenn, Paul Pate, Trevor Lee, Chris Ruper for this information ]

Balancer Nut Removal

A method I've used for removing the "Big Nut" on the front spindle of my Toro might work here. get the breaker bar, socket and short extension on the front crank bolt, and position the handle slightly below horizontal, toward the driver's side. Now, use a small floor jack, and place the jack pad at the very end of that handle. You might have to drop the starter and place something in one of the large flexplate holes to prevent the engine from turning over. Now, when you begin to pump up the jack, it's going to press up on the end of the handle, which will try to raise the car; the only link, though, from the jack to the car is the crank snout bolt. Can you visualize this setup? Perhaps a crude ASCII picture will illustrate it better:

 O======          <--- Breaker bar
        U      /
        \\    /
         \\_ /    <--- Rolling floor jack
         /   \
       O------O
[ Thanks to Bob Barry for this information. ]


Rebuilding Engine

[ Notice: ]Please refer to the Basic Tech section as well!
[ Notice: ]Please refer to the Engine Buildup section as well!

Now, various topics of concern for your rebuild . . .

In General

It's good to stop and ask questions if something doesn't seem right. Check, recheck, then recheck again should be the motto when rebuilding an engine. I've seen a lot of motors ruined by big egos.

Reference/Research
There are a few things you should know. I would highly recommend buying a book called How To Blue Print Your Engine, one of the SA or HP book series. A number of mail order book stores should have it. It covers basically every machining process and the why's and how's. Without thorough knowledge of the subjects in this book you will never be able to discuss all the options with your machinest.

Also get a chassis manual, Mondello's Catalog or Technical Reference, for the torque specs, and any other trivia about the engine you are rebuilding.

While complete blueprinting of an engine is a noble goal, its usually not necessary. If you are racing, and your class has very restrictive rules, then yes, blue print, bring every last part to its optimum configuration and size. But for a street engine, there are much cheaper ways to build power.

Stock Components
Though a Chevy's parts would be cheaper, you don't have to replace as many parts on an Olds to make it heavy duty, as the factory pieces were pretty beefy as is. In fact, the whole bottom end (apart from forged pistons, perhaps, in extreme situations) is suitable for 6000+rpm; if you don't have one, a rebuilt one from a major parts chain will automatically have all the good parts (if it is a non-windowed block, that is), and wouldn't cost much more than a lo-po Chevy 350 shortblock. Assuming, that is, you can get it with the 10.25:1 pistons.

For a mostly stock rebuild, the only non-factory parts you may be interested in is an aftermarket cam and intake, and a high-volume oil pump. Bearings, rings, gaskets, core plugs and other small items, of course.

Inspect the Engine to be Rebuilt
A full overhaul would be a full gasket/bearing/ring kit, new pistons, oil pump, cam, lifters, springs, and timing chain. On the machining side of it, plan on boring the block (honing at a minimum) and having a valve job done on the heads. This is the stuff that should be done at every rebuild past 100K miles for peace of mind. This also assumes the motor's never been apart before. There could also me some small stuff thrown in like worn out rockers and pivots, bad valves, etc that are fairly cheap by themselves, but can add up quickly.

Now, the spun bearing will throw in a couple of other expenses, like turning the crank (may have to get a new one) and either resizing the rod or machining the main caps, depending on which bearing spun. This can add up to a healthy bill but keep in mind that a good rebuild should last at least 100K miles of trouble free cruising. My advice is to honestly assess your financial situation, watch the infamous "Mightaswells", and if your forced to skimp on any part of the rebuild do it on the upper end of the motor that's easier to redo later on.

Machine Work
Your primary concern should be a 8 good bores - perfectly round when the cylinder heads are bolted on, with no taper, and piston to wall clearances at the exact minimum. Tight file-fit rings to go along. Along with the new pistons a complete engine balance job. Olds bolts and stud are pretty decent pieces (eg. 12 point rod bolts), but you could also replace some hardware with pieces from ARP.

A competent machine shop should not be able to give you an exact estimate until after they pulled the engine apart and measured every piece.

And don't let a wise guy tell you he can repair ten dozen cracks in a head, or bore 0.10" because they cannot routinely guarantee satisfactory work under this set of circumstances.

Don't skimp on the cylinder heads. A good valve seal + good oil control will lead to a long life of smooth idles. Consider refreshing that carb at the same time. A new tight engine pulls a good vacuum and should idle really smooth. Combined with a good engine balance and the engine will run better than new.

Goals For Engine Performance
You have to determine what rpms you want this engine to be running at. What transmission will you be using, what rear gears do you have, and what kind of driving will you be doing? The 403 I built for my Electra makes its best power in the 2500-5500 range; below that it still makes more power than stock, but to really make use of it I needed a higher-stall converter (2400rpm). This has diminished the responsiveness of the car around town, where at 30-40mph, with the 2.41:1 rear gears, I'm probably turning about 1200rpm. I don't drive it around town that much (it's our long-distance cruiser), so it doesn't bother me, but if I was going to drive it around town much, where I wanted good performance at part-throttle, low-rpms, I'd have gone with unported heads, a smaller cam and a tighter converter. I would have sacrificed full-throttle power, but it would have been more fun to drive down to the corner for some milk.

You can build your engine to maximize its power output at wide-open (100%) throttle, but this can diminish the performance of that engine in the car at the lesser throttle openings (say 10%-60%) you drive at most of the time. A drag car with a 4000rpm converter, 2-spd Powerglide and 600hp@6500rpm would be very unsatisfying to drive to work everyday, as it sputtered and lurched along in bumper-to-bumper traffic, because at 10%-50% throttle the drag engine is probably making half the horsepower that a stock 350 would make. Those are just some of the tradeoffs you have to consider.

Goals for Cost
You can do it on a low budget, but not *too* low. Spend the money in the right places (even if you have to sacrifice things initially, like the dual exhausts or a paint job), and you'll be happier in the long run. If you've already committed yourself (intentionally or not) to a full engine rebuild. Make that your first priority, and once that is squared away, move onto other parts of the project. The danger, of course, is that you can sink a lot of money into a project, and if you don't have enough funds to do everything at once, you place your money in the wrong places, and tie it up in an immobile project.

[ Thanks to Cliff Feiler, Mike Rothe, Mike Bloomer, Bob Barry for this information. ]

Balancers

Not sure about which CID's used which balancers, and if they're interchangeable, but I'd tend to lean on the not side, myself. My 403 met it's tragic demise that way. I'd found (used) the equivalent of the Fluidamper for Olds (Couldn't find any name on it, but rumored to be a Mondello product). Anyway, I just popped it on the 100K+ engine, and added an intake at the time. Ran great for a while, never really noticed any difference, but after a few months, the crank broke, right behind #2, sending everything in front of the fracture forward. Right through the block, into the water pump, and through the radiator. Messed it up hard. Near total loss on engine.

Anyway, the machine shop speculated that a faulty balancer most likely caused the problem. Didn't think you'd have to balance a balancer like that, still seems a bit odd to me, but I can't argue the fact that the engine was instantly reduced to shrapnel. Use incorrectly at your own risk, I guess.

Without getting to detailed on balancing componets let me tell you that I do not know what the factory did to engines. I was an engineer for Westinghouse and as such I balanced large steam and gas turbines for them. I learned that everything has a natural frequency which excites it to vibrate. That frequency is termed the natural harmonic for that piece of equipment. Because of operating rpm requirements sometimes it is necessary to change the mass of the machinery to move it's harmonic or natural resonant frequency. Hence the term harmonic balancer on an engine.

I would quess that GM accepted a mass or weight for each type of engine and made similar balance weights for them. I do not know but I wouldn't waste a lot of time discussing the point. If you have anything and you are of limited means as I have been and sometimes am I would try anything once. If you experience roughnes at different rpms then suspect the balancer on the engine. You better believe they are not put on cars and called balancers for nothing.

Besides static or mass natural frenquency there is dynamic balance to consider also. This dynamic balance has serveral critical rpms which are called first critical at about 1200 rpm and multipls of this first critical in this case 2400 and 3600rpms would behave differently but negatively. This is the true function of your balancer and hence it's true name is the dynamic harmonic balancer. I will bet money, and I never noticed one except to remove it on any engine that I have overhauled and replaced it as found. If you put a balancer on an engine that was not made for that engine some engineer at GM could tell you 10 reasons not to.

The problem with the dampers when they get old is the very fact that the rubber dries out, then the outer ring will slip, or worse, try to come off, and mess up the whole works. If it is a car that you plan on keeping for a long time, I highly suggest going to the local Olds dealer and purchasing a new one. Less than 100 bucks. The problem with using a "used" one, is just like you said, it could be in the same shape. The beauty of this is that the 307-455 balancers are the same part # at the dealership. I know, cause I was surprised to find out they had a new 455 balancer, which I found out later, it fit all of the V-8's. (Except the "unusual" applications, such as W-31, etc.) So they are available new.

If you are in a bind for cash, inspect the spare one you have, compare it to what's on the car and carefully inspect the rubber for obvious signs of slippage, cracking, etc. Ninety percent of the time you could get away with using that spare and have no problems, but if you are going to do some serious running with the car, go get a new one. One method of checking is to see if the #1 piston is at the top of it's travel, and the balancer reads no where near tdc.

[ Thanks to Charley Buehner, Gerald Christiana, Mike Rothe for this information ]

Balancing

If you replace anything in the reciprocating assembly (say, the pistons), you should plan on rebalancing the motor. Yes, we've all built motors without balancing, but you'll be a lot happier if you do. Crank, rods, pistons, rod & main bearings, rod & main bolts, flywheel/flexplate and harmonic damper are all included in the balancing act.

The rods are balanced for both reciprocating weight (small end) and rotating weight (big end). This requires a special fixture which holds the rod horizontally, with one end of the rod on a very low friction pivot while the other end is weighed on a scale. Match all the small end weights and all the big end weights, then add the total weight of each piston/rings/pin/rod/bearing/bolt assembly, add an amount for the weight of the oil which remains on the assembly, then install the bob weights on the crank throws. Obviously if you need to do any work on the rods, such as polishing, resizing, bushing for floating pins, or machining the famous "side grooves" on the big end, that must be done prior to balancing.

The crank is then spun on a machine that can determine where the crank is out of balance (uneven rotation). Weight can be added or removed to/from the crank (by either welding in metal, or drilling out a counterweight) to put the crank in balance. It sort of works like a dynamic tire balancer. I believe the crank is held in the balancer with bearings at either end. One end is restrained while the out of balance is measured on the other end. Counterbalance weights are drilled or filled as dictated by the balancer, then the restraints are reversed and the other end balanced.

[ Thanks to Joe Padavano for this information ]

Before Starting Rebuilt Engine

Before starting the engine, pre-lube the engine. See Initial Engine Startup below.

Block Boring

When you have the block bored, try to find a shop that has a torque plate for an Olds motor (but don't be surprised if you can't find one). A torque plate is a thick (about 2") chunk of cast iron which is intended to look like a cylinder head with holes where the cylinders are. This plate is bolted to the block and torqued prior to boring the block to mimic the distortions in the cylinder walls when the real heads are installed. This ensures that the cylinders will be as close to round as possible in the assembled motor. Again, this is not mandatory, and I'll be surprised if you can find a shop with such a plate for an Olds.

Honing
Even if the cylinders do not require boring they do require a bit of honing to seat the rings, so make sure that procedure is accomplished.

Another no-no is honing without torque/deck plates. You are spending all this money, and you want to guarantee a great final hone. When you decide on piston rings, ask the manufacturer for their recommendation on optimum hone for maximum life giving your driving style. Insist the machine shop follows it.

I've had very good luck using the cylinder hones that have multiple silicone carbide balls on the end of flexible wires. This type of hone (which I'm sure you're familiar with) needs to be purchased in the correct diameter to properly fit the cylinder bore. A good one will probably run you fifty bucks; a cheap one, well. I use a variable speed drill turning at medium slow speed (perhaps 3 to 4 revolutions per second) while I move the hone through the bore no faster than 2 complete in and out strokes per second (using copious quantities of oil in the bore). I've never actually timed myself or the drill, but these numbers sound good in retrospect as I imagine the process here at the key board.

One only needs to do this long enough to completely and evenly break the glaze and crosshatch (as Joe said) the bore. Also as Joe said: this step at a minimum, is mandatory. The bore (and block) needs to be cleaned very well afterward as you don't want any silicone carbide particles hanging around. If you have a slight ridge (a few thousandths) at the top of the bore, this process tends to take the sharp edge off of that ridge, but I personally wouldn't want to have much a ridge in my engine as new rings will undoubtedly touch it and premature wear will subsequently occur.

Over bore
I do believe sonic testing is necessary for .125 over bore in a 455 block. That's 482 CID with stock stroke!

[ Thanks to Roger Peterson, Bob Barry, Joe Padavano for this information. ]

Block Prep

Do a good job of deburring the block, paying particular attention to eliminating stress risers. In addition (since this is what I was doing earlier this evening), enlarge and clean up the four oil drain back holes at the top corners of the valley. These pass through the deck surface and connect with the drain back holes in the lower corners of the heads. I found that the ones in my block were close to half their intended diameter due to mismatches in the drilled holes.

Block cleanliness cannot be stressed enough. Clean the block and components thoroughly before assembly.

When the block is clean, paint the inside with electrical motor insulating paint (that strange redish-orange colored stuff), and the outside. After painting, get a set of taps and clean up every thread. Remove overspray from the inside of bearing seats and the cylinder bores. Check that every bolt hole, gallery, and block passage is clean, clear and not blocked.

[ Thanks to Joe Padavano for this information. ]

Budgeting the Rebuild

You can save a considerable amount of money if you do the tear down and build up. Expensive operations are usually: turning the crank, and align hone. Everything else is relatively cheap (just sometimes multiplied by 8 or even 16).

Now some cost estimates:
Hot tank and inspect block, heads, crank, and cam $200 - $300
Turn crank and new bearings $175 - $200 *
Cylinder head job, hard seats and valves $100 to $150 ea **
Lifters/rings/seals/timing chain/gasket set/bearings $250 - $300
So far your you've spent $825 - $1100

* Assuming the crank needs turning.
** Aluminum plating the valve heads is a little cheaper, and works very well.

If you get a low mileage block, you may not need to turn the crank, and save the better part of a C note. If the bores are just a few 0.001"s over size, it is often possible to knurl the pistons and reuse them. This is usually not the best idea. If you got a high mileage block, you may need to bore, which means pistons, so add a couple of C notes.

Pitfalls, the engine got hot and the heads have an amazing array of cracks. This is why you pay for a clean job and inspection. They can see a lot of potential damage by magna-fluxing the engine, prior to spending a lot of money on a bad part. Crank is too bad to turn, or is already well undersize. Same goes for the bores. About 0.060" is about all that is safe to overbore a cylinder without going to much inspection expense; and the casting may not be square enough to support more anyway.

Figure on spending close to $2000 for the engine, and then add the tranny. And this is if you do the tear down, and build up yourself, ie, the bargain basement. A shop will be at least $1000 higher, and YMMV.

Including their labor, for a rebore/ground crank/stock-type rebuild, with valve job and everything, figure around $1600-$2600, depending on labor charges, the performance machine work done to it (i.e. degreeing cam and balancing, which is highly recommended, 3-angle valve job, etc), whether they pull and install it or you do, what old things break and need replacing, etc. You could be pushing $3000-$3500, depending on what extras you need/want to be done (decking block, align-honing, adjustable valvetrain, etc.). These prices will vary with geography, though

You should be able to build a 350 to 400 hp small block well within a $2000 budget. Main areas to look at are camshaft, heads, intake and some gear. Stay around 9-9.5 compression. The Edelbrock 350 Olds they talk about produced 397hp with their cam intake, timing chain and a 9.5:1 block assm.

General machine costs alone, parts not included might run you something like (and I'd do them roughly in this order):

clean, bore & hone and deck resurface is about $200-225  total= $225
long block assembly might run $350-400 ........................  625
reconditioning rods is about $75...............................  700
crankshaft regrind $75.........................................  775
file fit rings $125 or so .....................................  900
heads reworked, bigger valves, machine guides, $250............ 1150

And thats parts alone, I wouldn't build an drag strip engine without paying close attention to the bottom end (balance, crankshaft and rod recond'). If you are assembling the engine yourself, you'll say a lot of money. engine yourself, you'll say a lot of money.

New pistons, cam, lifters, gaskets, etc with run you $1000-1200. So you are looking at $2500-3000 total. Thats provided you have a good intake/carb/exhaust/ignition system.

To stay under $2000, your best bet, imho, is go for cubes. The cheapest way to get an olds 350 to 350hp, is to replace it with a 455 :-). A running 455 could be had with a transmission for $500. Add a little cam (like a comp cams 268/268 .456/.456) and you could be at your target hp, for 1/2 what building a 350 would take.

Don't forget the rest of the car in your dragstrip build up... a higher stall torque converter and eat up 1/2 a grand easy, then there is tires, shocks, and maybe new springs.

[ Thanks to Cliff Feiler, Bob Barry, Doug Ahern, Jim Chermack for this information ]

Heads
I did the porting myself, but the other stuff will still eat another $300 not including the cost of the stainless steel valves ($190), valve springs ($70) and rocker arms ($90 Crane stock type). If I decide to go with an aftermarket adjustable conversion kit you can tack on $275-$350.

    $70 - purchase heads
    $20 - mag and clean
    $20 - misc porting stones
    $190 - valves
    $70 - springs
    $300 - adjustable conversion kit or $90 - stock type rockers
    $40 - resurface
    $80 - valve job
    $72 - bronze guides
    $80 - install guides

As you can see, a well done set of heads will cost between $732-$942 IF you do your own port work. Sorry for the LARGE dose of reality, but heads ain't a cheap proposition.

As you are talking of adding up costs, lets not forget to

 $40 - Weld center divider on the exhaust side of the head
 $25 - Block heat risers with Mondello alloy mix
 $35 - Mill exhaust side after having it welded
 $60 - Optionally mill the deck 0.060" for more compression
 $40 - Mill the intake side of the intake so it fits better to the head
 $125- $150 - competion valve job

How about using cast guides instead of bronze, better for street applications.
 $25 - Mill the guide tops for positive seals
 $25 - Seals

You could go with a Crowler or Comp cam and save a few $$. Use it to get a double roller timing chain.

Recondition heads (valve job 3 angle, includes truing deck and or decking)  $150.00
Bronze Guides Install  $75.00
Bronze Guides  $48.00
Stainless Valves 2.07/1.72  $128.64
Springs  $55.00 (302/351 Ford are the same)
Total  $456.64 (top of the line overhaul)
Plus $325 street porting if wanted (includes throat cut under valves and
pockets ported, AIR bump removed and exhaust completely smoothed. Intake was
not touched.
Totals $781.64

Well I got my heads back from the shop today.They seem ok so far, but the costs sure piled up: $449.39.

 Here's what they did:
 - Took off exhaust manifolds (frozen bolts).
 - Bead blasted exhaust manifolds
 - hot tanked heads and magnafluxed.
 - machined for larger valves
 - 3 angle valve job
 - machined spring seats .100" deeper (heads were shallow seat #5s)
 - installed new seals and machined seal bosses down to match spring seats
 - clean up cut on head deck
 - assembled to 1.750" spring height for the Edelbrock  springs.
This seems to match some of the costs I've seen quoted on the list but the costs of the valves, springs, retainers, keys and seals are not included in the $449.39
[ Thanks to Mick Gillespie, Mark Prince, Jim Chermack for this information. ]

Salvage Yard Parts
Be careful in terms of purchasing salvage yard components. In rounding up 455 parts to build an engine, and so far I've accumulated bits and pieces of 5. Out of the five all incomplete but two: I've salvaged one good block, another that will bore good at 0.010" over and another that is good but is already at 0.060" over. I have one almost usable crank already at 0.030" under, several good cams. I got five heads, none of which were useable, four, actually five unusable cranks. These engines were donated from under workbenches, and in clunker cars. Good 455 components are not impossible; but are starting to be difficult.

Parts Kits
Buying replacement parts in kit form can save you some money, as long as the components are from reputable manufacturers and suppliers. Some places will let you substitute high-performance parts for the factory replacement parts, for an additional charge.

Good luck with this; it won't be cheap. If you have the time and skill, you might be able to save a few hundred by doing it yourself, but then you'd have to spend much on that on the tools you didn't already have and couldn't borrow. Then again, you'd have all those neat tools.

Miscellaneous Parts
Also replace the fuel pump, water pump, distributor cap, coil, wires, and rotor. A rebuild on the distributor should be considered too. Use an aftermarket roller timing chain and sprockets. Do not use genuine Oldsmobile timing chain parts. The factory uses a plastic cam gear (for noise abatement) and that is always the first mechanical part to fail. It is amazing how split, cracked and hammered one of those plastic gears can get and still work; but it will fail. If the engine is under a good load, and the timing goes, it can wrack the entire valve train, when the pistons come up and slap the now stuck open valves. There are always two open valves.

[ Thanks to Doug Ahern for this information ]

Cams

Cam technology has come a long way since the 70s. Due to the poor exhaust ports on Olds motors, dual pattern cams are preferred. Use a roller timing chain. Get one of the modern cams w/lots of lift & little overlap. They give nice low to mid rpm power & will absoluteley double the gas mileage of a stock 455. The idle is smooth as silk, but the engine does come alive. Cam Design
A hydralic flat tappet cam's lobes are ground with a slight taper which spins the lifter and pushes the cam rearward. Also consider the rearward thrust of the cam produced by driving the distributor gear, which also drives the oil pump. The back of the cam gear then contacts the block preventing the whole assembly from going any further back. OTOH a roller cam has perfectly straight lobes. Of course to keep the cam from wandering around you must ues a thrust plate or cam button.

Excessive cam end play causes erratic timing and causes/is caused by (in a self reinforcing loop)timing chain stretch. Using a cam button does not cause any damage, and in fact stabilizes timing at high rpm. I can't think of any reason why a device that eliminates cam end play would cause premature wear on the cam. Even the timing cover shows no effect from the cam button, since the bronze button is the sacrificial (softer) component.

Mondello makes a bronze spacer that installs behind the cam gear (between the gear and the block) for use in setting up your cam properly. This is usually used with a bronze cam button.

[ Thanks to Walter, Scott Mullen, Glenn Connors for this information ]
Cam Nomenclature
Lobe centers are the apex of the lift for the intake and exhaust lobes. Lobe seperation is the number of degrees that seperates the two lobe centers. Overlap is the number of degrees that the cam holds both intake and exhaust open at the same moment. Cams are a very simple concept, but are extremely complicated in use.

Probably the best place to learn about these terms is from cam cataloges. Most have detailed information with pictures.

[ Thanks to Danny, Walter, Mark Prince for this information ]
Cam Tech
Note that a lot of duration numbers in ads are measured at a mythical 0" lift, which is almost impossible to measure but lends impressive duration numbers for advertising. The measurement at 0.050" was created to bring about a little more truth in duration advertising and comparison.

The whole reason for the .050" standard is that the cam grinders with very gradual ramps would show huge durations, because it took so many degrees to get the lifter up by .050", while other cams with more aggressive ramps would show less total duration at 0" lift. Perhaps you could generalize regarding cams from a certain grinder, but there's no simple formula for converting lift at 0" and .050". If there was, there would be no need for the different forms of measurement.

A few notes about Lobe Seperation Angle and Advancing or retarding the cam (valve) timing.

Varying Lobe Separation Angle:

Tighten Widen
Moves Torque peak to lower rpm Moves Torque peak to higher RPM
Increases Maximum torque Decreases Maximum Torque
Narrows Powerband Widens Powerband
Builds higher cylinder pressure Reduces maximum cylinder pressure
Increases chance of knock Decreases chance of knock
Increases cranking compression Decreases cranking compression
Increases effective compression Decreases effective compression
Idle vacuum reduced Idle vacuum increased
Idle quality reduced Idle quality improved
Open valve-overlap increases Open valve-overlap decreases
Closed valve-overlap increases Closed valve-overlap decreases
Natural EGR effect increases Natural EGR effect reduced
Decreases Piston-valve clearance Increases Piston-valve clearance

Lobe separation Angle characteristics:

Above 114 degrees = Extremely wide
114 - 112 degrees = Wide
112 - 110 degrees = Moderately wide
110 - 108 degrees = Moderate
108 - 106 degrees = Moderately tight
106 - 104 degrees = Tight
Below 104 degrees = Extremely tight

Advancing/Retarding Cam Timing:

Advancing Retarding
Begins intake event sooner Delays intake event sooner
Open intake valve sooner Keeps intake valve open later
Builds more low-end torque Builds more high-end torque
Decrease piston-in valve clearance Increase piston-in valve clearance
Increase piston-ex valve clearance Decrease piston-ex valve clearance
[ Thanks to Sean Meldrum, Bob Barry for this information ]
Picking a Cam
Figure out the range you want the engine to run in most of the time, choose the cam for that range, and then build the rest of the car (converter, rear gears, tire size) around that. Or, of one of those other variables is fixed (i.e., say, you're not going to change from the 3.08 rear gear you have in there now), then choose the other parts to match. If you don't, you'll end up building a car that you didn't want to build (i.e. a high-rpm cam with some 3.08 gears would be great for 70mph+ highway cruising, but that does you little good if you do your driving in-town).

A general rule of thumb is that older cams have more gradual ramps because the materials used in the lobes and lifters got chewed up with aggressive ramps. Now, with better quality metals, cam grinders can get to the same lift with less duration. All Olds passenger-car V-8's (except the '83-'84 H/O and '86-'87 442's) after about 1973 ran the same mild cam grind: .400" lift/~260° duration. Actually, some 260's and 307's may have had an even milder cam.

The H/O-442 cam in the 307's was a bit more radical: ~.430" lift, I recall. Of course, if you've got a roller-cam, so you can't just use the grind (and especially not the actual cam) from a late-70's 350.

Some helpful cam specs:
250 HP 350: .400" intake and exhaust lift -- 250° intake duration -- 264° exhaust duration -- 111° lobe centers.
310 HP 350: .400" intake and exhaust lift -- 258° intake duration -- 272° exhaust duration -- 111° lobe centers.
325 HP 350: .474" intake and exhaust lift -- 308° intake duration -- 308° exhaust duration -- 113° lobe centers.

You will have to elongate the rocker arm slots for anything above 0.500" lift or so. There is a tendancy to bind them and break the bolts or the umbrella seals. 455's typically like lots of duration so you could stay with a lower lift cam with more duration to make it run. With the lower compression you don't want to get too radical.

For automatics, 239° on lift at 0.050" is the highest number you want to run in order to keep power brakes. I have a 232°, 237° lift cam and still pull 15 inches of vacuum.

Any cam is going to cost you in the $100-$150 range. A nice factory style cam like the 350 4-bbl/4-spd cam (see the FAQ for specs) would be good for use with unported heads and stock valves; maybe a '69 H/O cam if you use larger valves and are running a 3.08:1 or 3.23:1 rear. Be aware that cams with a reduced base-circle require you to invest in longer pushrods. Not a big expense, just a little extra or gotcha.

[ Thanks to Bob Barry, Jim Chermack, Mark Prince, others for this information ]

Reusing the Cam
I'd like to use the original cam, but since it's been sitting, it probably could use a polishing. Is anyone familiar with the procedure for doing so? I imagine that you could simply do whatever finish procedures were used for a reground cam.

Check out Hemmings, I think I saw an ad for an outfit that could regrind your old cam to new specs. Assuming it isn't cratered with a wiped lobe. If you can resurface the lifters why not the cam?

Back in olden times you had to ship your bumpstick to Isky and have it ground with a whole new base circle so you could increase lift specs and duration. Real fancy technical designations like full race, 3/4 race, 1/2 race. Nobody but the cam grinders knew what duration and lift was being shipped.

No reason why an old but good used camshaft can't be rejuvenated if the blanks aren't available anymore.

[ Thanks to Bob Handren for this information ]

Replacing the Cam
Make sure you spring the extra $35 for a new set of lifters (and $20 more for the lifter extractor tool). If the lifters are stuck in the block, don't just replace the cam. Even assuming that you could do it, you wouldn't want to; the lifters develop a wear pattern with the individual lobe of a camshaft, and will cause excessive wear on a new cam's lobes.

If you were going to try replacing just the cam, I suppose you could unbolt the rockers, take out the pushrods, and pull the lifters up in their bores enough to clear the cam journals. Once you are at that point, however, you're only an inch away from pulling the lifter out of the bore anyway. Besides, it'd be much less than fun if one of the lifters decided to take a dive into the oil pan when you had the cam out.

[ Thanks to Bob Barry for this information ]
Degreeing the Cam
Yes, normally you just line up the dots on the sprockets when installing a cam. Unfortunately, many emissions V-8's reduced emissions (and power) by retarding the camshaft; sometimes the dowel on the camshaft would be a few degrees retarded, sometimes the dowel hole in the cam sprocket. When you add in production tolerances, it's quite possible that your cam will be *nowhere* near where it should be, even though you've matched up the dots.

This is one thing Mondello warns about in his tech manual, and that I've seen myself; even name-brand sprocket sets, with the dots matched, will retard the cam.

Now sometimes you want the cam to be retarded, sometimes you want it advanced, but most of the time you just want it installed "straight up". With a degree wheel attached to the front of the crank, you measure where certain camshaft events (max lift, opening .050", etc) occur in relation to TDC and BDC of the #1 piston; these are measured in degrees on the crank.

You can adjust the cam timing by using an offset bushing in the sprocket dowel hole, or using one of those multi-keyway timing sprockets.

And yes, if you could trust the dots, you wouldn't need to degree the cam unless you wanted to advance or retard it for some reason; I'd say that even on a stock Olds rebuild, you'd want to do it just to make sure the cam is where it should be.

[ Thanks to Bob Barry for this information ]
Cam Advance
Advancing a cam (moving the intake centerline more toward 0) will lower your Rpm power band. Retarding, the opposite.

If a cam specs say 106 deg intake centerline, putting the crank gear on the ( + ) or ( A ) will increase the bottom end torque. So, instead of a 2500-5500 cam it's now a 2000-5000 cam. COMPCAMS tech line told me it shifts it 500 RPM for a 4 deg change in valve timing.

Most timing gear sets have an advance/retard keyways of 4 deg instead of 2.

[ Thanks to Donny Arnold for this information ]

Cam Bank Angle, Lifter Size Considerations

This area is kind of long, but read it a couple of times, go back here and there to make sure you understand what it is saying. It is important.

Backround
Cam Bank Angle (CBA) has implications for blocks and heads made before 1968. For blocks and heads made after 1968, the default cam kit (39°) that most suppliers supply will work with your block and engine. So 1968 and later engine, block and/or heads, you are unaffected by CBA - you don't need to specify a different kit. Diesel and roller lifter 307s use larger lifters though.

Cam Bank Angle (CBA) affects big blocks and maybe small blocks. 1967 330 blocks used the 39 deg CBA. The factory parts book lists two different kinds of 67 330 blocks, though.

The short story is

Before 1968, use this chart:
330  #1 coded block (64-67 ALL were 45 degree and had .841" lifters)
400  #B coded block (65 only 442, 45 degree and had .841" lifters)
400  #E coded block (66-67 442 39 degree and had .921" lifters)
425  #A coded block (65 only, 45 degree and had .841" lifters)
425  #D coded block (66-67 NON - Toro all were 45 degree and had .841" lifters)
425  #D coded block (66-67 Toro all were 39 degree and had .921" lifters

1968 and after, use this chart, as all are 39° and 0.841" lifters:
350  #2 coded block (68-7? ALL were 39 degree and had .841" lifters)
400  #G coded block (68-69 442, 39 degree and had .841" lifters)
455  #F coded block (68-76 ALL 39 degree and had .841" lifters)
And all 260, 307 and later 350 blocks.

This can become a real mess and can twist the brain trying to understand the different combinations and what to look for. It can be difficult to understand at first, but just read it through a couple of times.

This effects two things when interchanging blocks and heads, the pushrod length and the pushrod clearance in its hole in the head.

Engines, Blocks
Oldsmobile engines from 1964 onward (330, 400, 425) originally used a 45 degree cam bank angle (CBA) and corresponding 0.842" diameter lifters. This angle is formed by the intersection between the cam centerline and perpendicular lifter centerline. By 1968, all Olds engines were using a 39 degree CBA and corresponding 0.842" diameter lifters. In the years between, 39 degree CBAs (and corresponding 0.921" diameter lifters) were used mainly on blocks found in models with premium engines, like Toronado's, 442's and Starfires. 45 degrees was being used everywhere else. The CBA also affects the pushrod hole angle in the heads.

Heads
45 degree blocks used 45 degree heads, and the same for 39 degree blocks and heads. Actually, the only difference is the size of the pushrod hole to accomodate a 45 or 39° pushrod angle (or CBA). If swapping heads between 45 and 39 degree blocks, you must watch for pushrod interference at the bottom of the head. To put 45 degree heads on a (455) 39 degree block, you have to bore the push rod holes to .562" i.d. Applies to "A" heads and some "B" heads. The simplist solution for pushrod interference is to just check for interference when test assembling the engine.

Power Output
The cam bank angle does not affect power output. The valves don't know the difference, as they just do what the tip of the rocker arm tells them to do; any differences in friction due to pushrod angles would be negligible.

You can NOT swap cams between the 45 and the 39 degree blocks. They will fit, BUT the cam timing events will NOT be as advertised. By degreeing the cam you will be able to figure all the specs out using a 39 degree cam in a 45 degree block. Those using a 45 degree engine should call the cam manufacturer to have them grind it for that engine. Will only cost a couple dollars more. Big lifters were only used in the 66-67 engines. Toro and 442. 425's with big lifters are only Toro and will guarantee you a 39 degree block. They have become very difficult to find the lifters and when you do they will not be cheap. Usually around $9.00 per lifter. The other .841 lifter is common, and will run usually less than half the price of the big ones.

Identification

CBA Lifter Notes
45 0.842" Small block: Block IDs 1, 2 - all 330's. 1968-1970 350s used ID 2 as well, so check for block date code. Head IDs 1, 2, 3, 4.
45 0.842" Big block: Block IDs A, B, D, E. Head IDs A, B, and some C.
39 0.921" Big block: Block IDs D, E with drill spot on vertical rib located on timing shelf area (see below). Head IDs B, C.
39 0.842" Big block, small block: Block IDs F, Fa, G, L, all small block IDs 3 and after. Head IDs 5 and up. Most Olds engines 1968 and up. Exception: diesels and late 307's w/7A heads.
39 0.921" Diesels and 7A head 307's.

Notes:

If the engine is original to the car it was pulled from, you know the year of the block and heads.

Push Rods
In the case of pushrod length, use the pushrods and lifters which are correct for the _block_ you are using. Note: The parts book actually lists three different pushrod lengths for the 330; 8 5/16", 8 21/64" and 8 23/64". All 350s use a pushrod length of 8 17/64". In the case of the clearance in the pushrod hole in the head (which is the rubbing you ask about), the easy solution is to slightly enlarge the holes in the head to provide greater clearance.

Interesting note about pushrod length vs. CBA. In all cases (big block as well as small block), the 45 degree motors use longer pushrods than the 39 degree motors. Since the head castings and rocker arms are the same, I would have assumed that the narrower CBA, which puts the lifters closer to vertical, would require the longer pushrods. Yes, the lifters are the same length in both cases. Am I wrong; is the 39 or 45 deg CBA not the angle from _vertical_?

[ Thanks to Jim Chermack, Joe Padavano for this information. ]

Checking CBA

There are a couple of ways to check for cam bank angle:

Basically, the way it worked out was that if the early (pre 1968) big block had 0.921 lifters, it was an advanced [for the time] 39-degree block, and if it had the normal 0.842 lifters, it was an old 45 degree block.

Anyhow, the presence of the drill spot means a 39 degree block and heads. Easy to spot, too.

Implications
45 degree cams can be more difficult to find, but any REPUTABLE supplier can supply the grind you want in the configuration you need [Mondello, Dave Smith, etc.]. You will probably pay more for the cam, but you can use the cheaper 0.842" lifters.

0.921" lifters are more expensive- like $100 vs. $35 for .842" units, per set. So you pay more for lifters, but can use the cheaper 39° cam.

Affects of Wrong CBA parts
If you were to install a 39° cam in a 45° block, the cam will effectively be installed 6° advanced, and for the other, it will be installed 6° retarded (assuming, of course, that the cam is installed "stright-up" relative to the cam gear, not relative to the #1 cylinder-else the other bank would be 12° off). With this installation, one cylinder bank would have its camshaft timing advanced by 6°, while the other would be retarded by 6° (assuming the timing-chain set would install the camshaft straight-up in relation to a 39° engine).

However, if you degreed the cam according to the #1 lobe, however, the odd bank would be installed straight up, but the even bank would be 12° retarded!. The reason it's not 3° advanced and retarded (totaling the 6° difference in the cam bank angles) is because the camshaft degrees are measured at the crank, which is double the actual camshaft degrees (hence, the 328° W-30 cam did not have a lifter lobe that was above the base circle for almost the entire lobe, but rather only for 164° of the cam's circumfrence.

The engine is not going to run right with the wrong CBA cam, no matter what you do. Indexing it to one bank would only make the other bank worse. Adjust the timing won't work either. The motor will run very badly and loudly at idle, but it will run. Once you got it above maybe 2000 RPMs, it will be fine, but you can hide just about any mistake at that engine speed. The best you can hope for is that one bank will see enough improvement in performance to offset the degradation of performance on the other cylinder bank; it's likely, however, that your performance will be worse than with a proper 45' cam, and I don't think you can count on it being better. Spring the $120 for the correct cam, and $40 for the correct lifters; you'll be glad you did.

I had the wrong cam in my 66 98 for about a month back in 87. Basically it ran ok from 2000 RPM and up, but idled very, very poorly. Eventually the builder discovered that he'd put the wrong one in and put in the correct one. So. It will run (cough, choke, sputter, cough), but not how you'd want it to.

It will work, but it will run absolutely terrible. My '65 442 had a 39 degree in it when I got it and it made no power, ran rough, and got sh*@ty gas milage. I put in the correct 45 degree cam with similar specs, if not more mild, and it screams and gets twice the milage. Either get a 39 degree 455 block for your 425 crank, rods and pistons or get a 45 degree cam.

[ Thanks to Chris Witt, Bob Barry, Chris Fair for this information ]

Carburetor

Consider rejetting the carburetor to more or less match any changes you have made to the engine. If you are basically trying to reproduce the stock performance, this is really optional. There are some nice articles on choosing jets & metering rods for your cam & other needs. This produced a nice smooth running engine w/lots of instant throttle.

Going from a 2 to 4 bbl intake on a 350, a 600 CFM carb should be enough. Again, you have to determine what rpm range you want this engine to make power in (based on the rpms it will see when you are driving it most of the time, not only the occasional full-throttle from a stop), and choose the components to match that power curve.

[ Thanks to Bob Barry for this information. ]

Cleaning

Don't skip hot tank and magnaflux, even though it costs a few bucks.

You can take the block or whole car for that matter, and use the engine degreaser at the car wash. Let it soak a while, or better yet, spray a couple cans on the engine about 30 minutes before arriving at the car wash. That will help the degreaser soak into the crud. The high pressure water will take care of blasting the crud off if the degreaser has soaked in down to the metal or iron.

I just finished this process on my 455 block, I first took the car to the local car wash, soaked the motor with Castrol Super Clean, Bleche White, Simple Green & the Carwash formula, let it sit for half an hour and then rinsed the toxic combo off. Most of the goo came off but there were the usual nooks & crannies, so I yanked the motor and slapped it on a stand, hosed the whole thing with oven cleaner, let it sit for a couple of hours, came back & scrubbed everywhere I could then went to town with the Berrymans Carb cleaner. The result was a block that appeared to have been vatted or blasted. Lots of work, but it looks great!

Try A product call S100, You can pick it up at a motorcycle shop. It works great and you only need a garden hose not a pressure sprayer.

One cleaner mentioned was Castrol's Super Clean, it does a good job. But last night I used some plain old Oven Cleaner (the type you don't need to heat the oven with) on the front frame and crossmember of the race car, and it did a real good job. Cleaned it up good enough to let me use the sandblaster on it today. EZ-OFF cold formula is probably the best engine cleaner I have ever found. But you are right about not using it on any painted surface you want to keep, it's a killer. Jim Harrell Harrell17@aol.com

[ Thanks to Jim Harrell, Scott Wheeler, Ken Snyder for this information. ]

Cylinders

I'm not one to build an engine with much cylinder wall taper (difference in cylinder wall diameter as measured from top to bottom at multiple locations). A couple of thousandths? O/K, if I'm not going to race. How much is a couple? For me it's two, maybe three. Four is too much. Also check for cylinder wall out-of-round. This has a lot to do with how (and if) new rings will seat. A hone won't improve on this.

[ Thanks to Roger Peterson for this information. ]

Dipstick Tube

Removal
OK, the big question you have to answer is "Is the dipstick really completely missing, or is it just broken off in the block?"

If the old one was removed, and is completely missing, then it's an easy job to tap in the new one. I tried using vise-grips near the base, loosely holding the tube, until I discovered the trick of using a larger bolt with a built-in washer (something from my body panels screw bin), which I used to tap it right in.

If, however, the old stub of the dipstick tube is still in the block, it's a bit harder. You'll have to screw in a coarse-thread bolt whose outside diameter is just bigger than the inside diameter of the broken-off tube, and use a pair of vise-grips to yank it or hammer it out of there. You might also be able to use a sliding-type dent puller with the right screw. To get at this, you'll have to remove the exhaust manifold on that side (avoid breaking off the exhaust manifold bolts; that's an even worse job), the crossover tube, and maybe some other things that get in the way (steering shaft, starter, etc.).

If all else fails, you can jack up the engine, remove the oil pan, and tap out the tube from inside the crankcase. I hope to hell the old 1 is NOT broke off in the hole..if it is...HAVE FUN...otherwise..all you have to do is inert the tube in the hole and press it in...it may be a lil tight...but if you twist is as you insert it it should ease right in...Hoagie

[ Thanks to Bob Barry for this information. ]

Installation
The recommended way is to use a tool which looks like a piece of tubing which has an inside diameter which will allow it to slip over the dipstick tube. The bottom portion of this tube is cut away for about 180 degrees to allow you to slip it over the dipstick tube. You then pound on this tool to force the dipstick tube into place. As an alternative, I've also used a long screwdriver applied to the upper hoop and gently tapped into place while moving the screwdriver around the periphery of the hoop. Note that while I've had success doing this, I've also damaged a tube or two when not being careful.

[ Thanks to Joe Padavano for this information. ]

Distributor/Ignition

If you are rebuilding the engine to be close to stock, this is really optional. But, if you really want to set it up correctly, the distributor (or advance curve) is recurved to match the rest of the car. A competent hot rod shop can do this. Consider though, a newer breakerless distributor (HEI, etc). These will do wonders for reliability & driveability. They will still have to be recurved though. Kits w/instructions can be bought for you to do this yourself.

[ Thanks to for this information. ]

Distributor Install

Genuine Old Racer's Trick: with engine at #1 firing position, stuck your paint pen [you *do* have one, right!? get one if not!] into the dist'r hole and MARK THE CAM GEAR. Any little dab will do.

Later, after you've turned the motor about 37 times installing the tork converter, etc. and then you want to install the dist'r... all you need do is line up the timing marks, peer down into the dist'r hole... see paint: #1 firing; no paint- #6 firing position.

[ Thanks to Chris Witt for this information. ]

Engine Paint

It's always good to match your paint before getting rid of the old because some companies get the color close, but not close enough. You will find each seller's paint shade differs a little bit.

Urethane, if you can get it, lasts longer. Some sources for correct colors:

Silvery Metallic Blue
Bill Hirsch's Old Blue paint
Brother's Olds Blue paint
NAPA Auto Parts Olds Blue paint
Specialty Olds Blue paint
Year One Olds Blue paint
Bronze
Brothers Auto (800-442-7278) bronze engine paint is correct.
Gold
Check Plasti-kote Cadillac gold. It is a little bright at first, but it mellows out after a couple of days.
Check Dupli-color Ford gold. It is very close.
Red:
Ford red is real close to Oldsmobile red.
Any color
Bill Hirsch in N.J. Very good color matching.
Fusick's - about $9 a can.
NAPA - about $4-5 a can.
Supercars Unlimited (503-244-8249) - about $8 per can. Correct color is guaranteed.
1964-1972 330/350 gold, part number 14-214
1965-1969 400 bronze, part number 14-218
1965-1968 425, 455 red, part number 14-260
1970-1985 350/455 blue, part number 14-216

GM went to black for a minor heat reduction improvement. Black color radiates heat more effectively then lighter colors. Look at any race car engine, most are black. Like your radiator is most likely black. White REFLECTS heat, black absorbs it, but black also radiates it as well. If white was a better color, your pots, pans, and skillets would be white instead of black. Just the laws of nature!

Others may have mentioned this, but the single most important prep for an engine is a thorough degreasing. Using a pressure washer is only the beginning. I have followed that up with a complete scrubbing using lacquer thinner and a small wire brush. Follow this up with a laquer thinner wipedown, then do not touch the surface with bare hands prior to painting.

Also, I've seen suggestions of using paint primer first. My own preference is to not use primer under engine paint for two reasons. First, most primer is not designed to tolerate the high temperatures, and second, you want to keep the paint layer as thin as possible. The cast iron expands and contracts with heat, and the thinner the paint layer the easier it is for the paint to move with the metal and not crack and flake off. The factory did not use primer under the engine paint.

Finally, I've had excellent results with Fusick's engine paint. I've used the 400 cu in bronze, and while the color looks to be an excellent match, the paint is quite thin. Unfortunately the lightness of the color is a function of the applied thickness (as with all metallic paints), so if you try to shoot several thin coats (as one normally would), you'll end up with a lighter color than factory. Shooting the paint heavy to get the right color unfortunately results in runs (which would duplicate the factory paint job).

[ Thanks to Walter, Danny, Mark Prince, Everett, Todd Wallin Greg Beaulieu, Thomas Martin, Joe Padavano for this information ]

Frame Mounts and Motor Mounts

Before Installation
I just finished putting in the left motor mount on my 86 Cutlass. I would now like to pass along a couple of helpful hints I just learned.

1. The very second you take the new mount out of the box, be sure to clean out the bolt holes and make sure that there is no tough molded rubber left in them. After it is between the block and the frame is NOT the time to find out you should have done this. Bolts don't like to travel through this stuff for some reason.

2. If you ever have some inexplicable noises or bumping or vibrating, be sure to check the motor mounts. It sounds really crazy but I swear that new mount has eliminated a severe thump I used to have upon acceleration (duh!) and a rattle I thought was in the dash. I chased that rattling noise all over the front of the car but with this new mount the noise seems to have disappeared.

3. I'm so happy about this new mount and suprised at how many problems it solved, I think I will blame everything on bad motor mounts. Vibrations under the hood? Bad motor mounts. Thumping on acceleration? Bad motor mounts. Flat tire and blown headlight? You guessed it! Bad motor mounts.

[ Thanks to Brian Shankle for this information. ]
There is no difference in these years. 69-72 455/400 cars all use the same mounts. We have lots of them. 66-68 400 cars used a diffent mount that is very hard to get. They are different. They have the same bolt spacing as the 330/350 mounts. Jim Chermack

The Skinny
With regard to picking the right frame pad mount and motor mount combination, The engine crank centerline will be in exactly the same place, between a big block and small block. This is crucial for tranny alignment, fan location in the shroud, etc). The engine appears to sit higher because a big block is one inch taller than a small block - the heads and carb flange are obviously further away from the crank centerline. The problems with clearance, etc., come with mixing big block motor mounts with small block frame mounts, or vice versa.

My factory parts book says that all 66-68 big and small block cars use the same frame and motor mounts. These frame mounts should measure approximately 1.6" from the two top bolt holes to the cross bolt hole (centerline to centerline). Note that a big block will put its valve covers closer to the power booster than a small block, as the big block is about 1 1/2" taller. Olds had "notched" valve covers with indentations to clear the power booster and the A/C in these applications. Another interesting aside is that the power booster on my 66 (an original unit) is smaller in diameter than the one on my 67 parts car - and the 66 400 does not use the notched valve covers. In addition, the 67 inner fender panel on the driver's side has an indentation to clear this larger power booster, while the 66 inner fender does not. I always assumed they were the same.

There is no difference in these years. 69-72 455/400 cars all use the same mounts. We have lots of them. 66-68 400 cars used a diffent mount that is very hard to get. They are different. They have the same bolt spacing as the 330/350 mounts.

Through 68, all big and small block A-body Oldsmobiles used the same frame mount, part no. 383563. In 69, Olds went to a new design of the rubber motor mount, requiring a redesign of the matching frame mount on the big block cars (350s retained the 68-earlier design). In both cases, though, the engine crank centerline sits at the same height for both big and small blocks. Since the front cover is the same, that means the water pump also sits at the same height. All you need is to use the frame and rubber mounts for the _car_, not the engine. When installed with the correct mounts, the big block will look like it's sitting higher because it _is_ an inch taller that the small block. That's why the 70 W-31 uses a taller foam ring on the O.A.I. adapter than the W-30.

My 1972 assembly manual shows the part number for the 455 frame mount as 402953 and the 350 mount as 404752. Only other part numbers on the page is motor mount numbers and bolt numbers. It also shows both set of mounts sharing the same holes on the frame. The page in the assembly manual is called "Power Plant to Frame" part numbwer 410124 series A Year 72 manual section 6-1 page 130.

You will need the correct frame mounts in addition to the motor mounts for your 455 to sit correctly. You can install the 455 using 350 frame and motor mounts, however the engine will sit about an inch higher in the car, which may cause a problem with your headers. It might also cause a problem with your O.A.I. air cleaner.

The thing to remember is that both the frame mounts and the motor mounts differ between big and small block Olds motors.

It sounds like you may have the wrong ones or ones from the wrong year. Olds played around with motor mounts during the A-body years, and the bottom line is that: 1) Frame and motor mounts go together in matched sets (that is, a certain frame mount needs a certain motor mount to match), 2) Big and small blocks used different mounts, and 3) Different year mounts may not match, even for the same body style. I've tried unsuccessfully to compile a dimensional listing of the various frame/motor mount combinations.

That's right. That's why if you use a big block motor mount on the taller small block frame mount, the engine will sit too high. You either need the correct big block frame mounts to match the motor mounts OR the original small block motor mounts matched to the small block frame mounts. This second combination will bolt up to the big block with no problems and will allow it to sit in the correct location. I also remain mystified by Lansing's use of the two different designs, and can only offer my hypotheses:

1) The big block mounts have been tuned for NVH response, which would explain their different size. In this case, you may notice more vibration with the small block mounts, but no functional effects.

2) Due to the additional torque, the big block mounts are stronger, potentially incorporating the "fail safe" design of interlocking metal parts to still retain the motor in the event that the rubber cracks. Keep in mind that GM went through a massive recall in the late 1960s to retrofit limiter straps on Chevies due to a rash of failed motor mounts. This mentality may have spilled over into the design of the big block mounts. It is interesting to note that through 1968, all Olds motors, big and small block, used the same part number motor mounts and the "tall" frame mounts. In this case, if you are using the small block mounts on a big block, I would ensure that the rubber motor mounts are periodically inspected for deterioration, and consider adding a torque strap to the driver's side of the motor.

Again, these are theories only; unfortunately I have no proof one way or the other.

[ Thanks to Mark Prince, Jim Chermack, Joe Padavano for this information. ]

Motor Mount Dimensions
What I learned from measuring every motor mount & frame pad on hand: (frame pad selection was limited to 1968 442 and 1971 Cutlass 350)

[----Side view of Olds motor mount, lying on its motor face----
[
[              ___      Lip
[      TOP     \  ---___       Frame
[              / \     X---___
[             /     \ X       ---_
[            /         \       __ |
[           /             \   |  || --------
[          /                 \ -- |   ^
[         /  |                  \Y|   B: Motor boss to hole along
[        /__   __________         |   |      motor bolt axis
[______ |___|||__________|\      /  __v_____
[               Motor     \\\  /
[            |              \/
[            |                  |
[            |                  |
[            |                  |
[            |<------ C ------->|
[      Motor bolt centerline to mount bolt
[   centerline, parallel to engine boss face

X is (hidden) lip that fits on the top of the frame mount.
Y (just below the thru-bolt hole) is where some SB mounts have another lip, which prevents their fitting down over the pad on a BB frame mount.
Msrmt A= between that lip and the motor mount thru-bolt centerline. "Hole separation" below is distance from hole centerline at mount/ block interface to motor mount bolt hole center, disregarding the fore-aft offset: sqrt(B^2+C^2).

A       B     C   Hole Sep'n   ID#           Application
1     1.5   2.25   2.70       ACM 2308    unknown
1.5   2.0   1.25   2.35       401341     '68 Vista Cruiser, 400 CID, Old
1.5   2.25  1.25   2.57       -none-     '68 Vista Cruiser, 400 CID, Old
1     1.5   2.0    2.5        408452      unknown
1.5   2.0   1.5    2.5         none      '67 Cutlass 350-AT recently
1.5   2.0   1.25   2.35       394198      unknown
1     2.0   2.25   3.01        none       unknown
1.5   2.0   1.5    2.5        383564      unknown
0.75  1.75  2.25   2.85        2328       unknown
0.75  1.5   2.25   2.70        none      '78 403 OEM
1     1.5   2.25   2.70        none       unknown
1     1.5   2.5    2.91        2328      "Type 410814" KF Made in Korea
                                          F264 BOS Auto. Prod. [from NAL]
7/8   1.5   2.25   2.70        M2328     Made in China
                                          F334 BOS Auto. Prod.
1.4   1.88  1.63   2.48        2261      Korea, JCWhitney #37-9880, [1990]
1.0   1.50  2.50   2.90        23##      Chermack's
1.38  1.88  1.50   2.40        2261      Chermack's

Jim Chermack says there are at least 3 main varieties of Oldsmobile A-body motor mounts:

2286 = '66-67 big block [have a bolt thru the rubber?]
2261 = Small Block
2328 = 69-72 big block
2293 [or 2294?] = Newer version of 2328, fits 69-72 BB -and-
                  '73-up Cutlass also.

Ramifications:
"A" is pretty critical- if the lip is too close to the thru-bolt hole, there is no way the mount will mate with that frame pad.

"B" is how far the thru-bolt hole is offset sideways.

"C" is how far the thru-bolt hole is offset downward.

Span between thru-holes on frame pads should measure 2*B + width of block where mounts bolt on.

[ Thanks to Chris Witt, Jim Chermack for this information. ]

Frame Pads / Frame Mount Dimensions
And now... Frame Pads

[                         ----
[                        /  O |
[           /--------------.  |
[          /      =[       ]  |  TOP
[         | O     =[ PAD   ]  |
[          \      =[       ]  |
[           \--------------   |
[           |    | |     \  O |
[           |    | |      ----
[           |    | |       ||
[           |    | |       ||
[           |    | |       ||     1-3/16"
[           |    |  _______ | ___/
[           |    | /    O  | ------9/16"+
[         ==-===============-==  -- 0
[           |    | |    |  ||
[           |    | |    |  ||
[           |    | |    |  ||
[           E    D C    |  A \
[                       B     \
[                              0
0 = Index = Zero point = top two frame bolt holes' centerline
A = top of frame pad
B = Thru-bolt [motor mount bolt] hole
C = pad starts to fade away
D = End of pad
E = single lower hole centerine

  
A B C D E
SB *1: 0.125" 1.5" 2.25" 3.0" 4.5"
BB *2: 0.125" 1.5" 2.88" 4.0" 4.5"
*1= from 1971 Cutlass S with 350 motor.
*2= factory 1968 442 frame pad was measured.

Basically, the BB pad is about 1/2" longer, extending nearly to the bottom bolt of the frame pad. Some motor mounts have a lower lip which is supposed to fit over the (smaller) pad [2.5" max pad length], and would interfere with the larger pad.

Both these frame pads had the same measurement from top edge of pad to thru-bolt centerline, but.... there must be some pads with the hole closer to the top of the pad, for the numerous motor mounts which have a measurement of only 1 inch to fit.

It is left for the reader as an exercise to determine the effect on motor position, etc. by mixing & matching mounts & frame pads. All the pertinent Olds V-8s share the same size (width) block at the motor mount bosses, so that is not a factor.

[ Thanks to Chris Witt for this information. ]
Hard to Reach Frame Pad Bolts
There are two holes for a socket to go through to reach a bolt, on the bottom of the crossmember. Tight, but a thin wall socket will fit.

The third bolt can be reached with a wrench through a hole in the rear of the crossmember.

[ Thanks to Bob Blanchard for this information. ]

Implications of Using the Wrong Frame or Motor Mounts
The 455 frame mounts are lower. You can bolt the engine up using the 350 mounts, but you'll end up with driveline vibration because the angle of the front universal will be wrong.

The problem of fan hitting the shroud comes about when rubber mounts for the engine are matched with the frame mounts for the car; the later mounts place the cross bolt (the bolt that connects the rubber mount to the frame mount) lower in the car - using these rubber mounts with the early frame mounts will make the engine sit high.

Headers will sit lower than normal, causing them to get scraped and be dented.

[ Thanks to Scott Woodworth, Joe Padavano, Ken Rotten for this information. ]

Big Block or Small Block Frame Mount?
I finally put a SB & BB frame mount side by side to view the difference. Hmmmm.... more meat on the BB unit, and different hole location.

For whatever it's worth, here are some dimensions on 350 & 455 frame mounts that may help you determine if you have the correct frame mounts. The only similarity between the 350 & 455 frame mounts is the dimension between the lower single hole and the upper two holes. It is 4 1/2" for both. The difference is in the location of the horizontal hole for the cross bolt.

Here are some part numbers for Anchor motor mounts:

[ Thanks to Chris Witt, Ali Zalzala for this information. ]

Big Block or Small Block Motor Mount?
When looking at the underside of the B/B mounts there is a metal tube, or whatever you want to call it, that goes from side to side where the motor mount bolt goes thru, as if to add strength to it.

[ Thanks to Everett Horton for this information. ]

Cutlass Engine Offset
Previously I mentioned the Hot Rod/Car Craft item about engine offset in the Olds A-body cars. Now I remember the exact quote that told me they didn't know what they were talking about. The response to the tech question had indicated that engines were offset in Cutlass Supreme and Cutlass S models, but not in 442s in the 1970-1972 model years. Here's the problem with this statement: the Cutlass S and 442 are EXACTLY the same body, with EXACTLY the same engine placement.

In fact, in 1972, when the 442 was demoted back to an option package, the Cutlass S WAS the 442. Both the Cutlass S and the 442 use the "77" Sport Coupe and "87" Holiday Coupe body styles. Frames, motor mounts, crossmembers, etc, etc. are IDENTICAL between these two. Basically, Petersen Publishing doesn't know what the heck they're talking about. And yes, I have put big tube headers in a big block 71 Cutlass S with no problems, as well as in a 72 Cutlass S-based 442 with a 350. Just please don't tell anyone I once owned a car with a small block, OK?

Here's the parts end of things for this thread. GM Oldsmobile parts book states:

  1. Engine Mounts (PN 406436 are the same for 69-72 400/455 A body and are also the same (PN 404461) for all small blocks 68-72.

The 68-72 Assembly Manuals State:

  1. Frame mounts are also like the above. Same for all 400/455 68-72, and 350 from 68-72.
  2. T