This may be a silly question, but I honestly
cannot remember...
Motor mounts are interchangable left to
right and vise-versa, correct?
I belive that goes for the 350's as well?

 

Actually, not so silly. Yes, on A-body cars and on 1971-up full size cars the mounts are the same on both sides. Interestingly, the 1965-1970 full size cars used different RH/LH mounts, Anchor P/N 2262 and 2263.

And once again, ALL Olds motors have their motor mount attachment provisions in the same places, so yes all 1964-1990 Olds V8s mount the same way.

 

^^^ Thanks again Joe!
It's nice to learn.

 

Remember if you take out a 350 and install a 455. You use the mounts that are for the engine you are taking ou,. on the "A" body cars.


"Joe"
Is that the same way on the big body cars ?

Gene

 

Actually, with the exception of the 1969-1973 A-body cars, every 1964-1990 RWD Oldsmobile uses the same motor and frame mounts for both big and small block Olds V8 engines (as usual, excepting the 1964 394). For example, all 1964-68 A-body cars use 2261 mounts for both BBO and SBO. All 65-70 full size use the 2262/2263 combo. All 1974-1988 A/G cars use the 2328s. All 1971-1990 B/C/D cars also use 2328s. This is why I specifically do not call them "350 mounts" or "455 mounts".

 

And for anyone who has had a difficult time with the aftermarket mounts,
I have 1 last set of N.O.S. == OEM GM == Motor Mounts for the 1965 - 1970 OLDS FULL SIZE application!!!!!!!!!!!!!!!!!!

Best to call me --- Craig --- 516 - 485 - 1935....New York...

 

Craig,

Considering that 1) this thread is not about full size motor mounts and 2) we have a Classifieds forum for ads, please use that forum instead of hijacking threads as your last three or four posts have done. Thanks.

 

This is the question that has always bugged me, What was the purpose of using two different motor mounts in the late 60-early 70 A bodies?

 

Since you asked nicely... one more time.

Up until the late 1960s, GM motor mounts were simply just two metal brackets with rubber molded between them. In normal use, one is in compression, one is in tension. Eventually the one in tension (driver's side) would crack and separate, causing the engine to torque over to the right. Coupled with the rigid rod-style throttle linkage of the day, this led to jammed throttles. GM had a massive recall in the late 1960s to correct this, primarily by installing a cable from the LH exhaust manifold to the upper control arm cross shaft. This cable prevented the motor from moving too much if the mount separated.

Olds started redesigning motor mounts in the 1969 model year by modifying the metal brackets to incorporate an interlocking feature such that even if the rubber separated, the interlocking feature prevented the motor from torquing over. I guess Olds figured that the big block A-body cars were the most likely to see frequent full throttle acceleration, so these were the cars that got the modified mounts first. The interlocking feature made the mounts physically larger, which is why the frame mount is different. This is the mount that is now available as the 2328 mount.

For the 1970 model year, Olds engineers figured out how to incorporate the interlock feature within the 2261 package, so the SBOs got the same safety but with the smaller mounts. All 2261 mounts sold today have the interlock and will retrofit to the earlier cars. This is why there are two mount versions for the 1969-72 A-body cars. Starting with the 1971 model year, the full size cars went to the 2328 style mounts also.

 

^^^ Thank you again Joe.
This one's good to print guys, lol.

 

Thanks Joe, always helpful to know the back ground, and I as well as others appreciate you patience on this information.

One other question though, Are the 2328 mounts "stronger" to any measurable degree, or is that the engineers figured out how to make the mounts in a smaller size? In other words if two A-bodies with 455's were equal in every way and drove exactly the same way, would the 2261's wear out faster or break sooner?

 

That's a really good question and unfortunately I don't have hard data to provide a definitive answer. My engineering judgement says that the larger 2328s have more surface area in the rubber part and thus SHOULD be stronger, but that's about as accurate as the "butt dyno" as far as real data is concerned. The only other thing to consider is that by the mid-1970s, Olds used the larger 2328 design exclusively (including on the pavement-ripping 307s). This may be an engineering decision or may just be a cost decision to only use one design.

 

Thanks Joe, I would say that is more economics than engineering by that time, as you said the 307 was not known for its motor mount ripping capacity.