I noticed that there are 2 different size Engine Frame Mounts on one '69 to another I have. They are exactly the same except one set is about a half inch taller than the other. Both were small block cars.

I'm trying to figure out why one set is taller?

A '70 I have, which is also a small block car, has the shorter mounts.

Any info would be appreciated.

Bill

Hi Bill,
frame mounts are the same for 69-70 327,350,400 454 except for 350 2bb engine RH side
That mount was a different part#..I think it was because it was a lighter duty mount.The 400 2bb and all 427-454 engine mounts were reinforced more.
But the heights were all the same.
Hope this helps,Jim

Jim,

Appreciate the reply.

I've got 4 full size cars with the engines out (3 '69's and a '70). Two cars have the lower mounts and 2 have the higher mounts. It is pretty much visible to the eye, which originally caught my attention. I then put one set side by side to the other set and there is about a half inch difference.

I can take some pictures if you would like.

Bill

Hi Bill,
Don't know what to say.All my research on part numbers shows frame mounts all the same.Are any of the cars 400 small blocks?That may have something to do with it,similar to big block mounts.Or possibly a GM part supplier difference?I've seen that many times.Part number stays the same and part is updated,etc...
Jim

Bill,
Just had another thought here.I have a complete copy of the '65-'69(including early '70)engine motor mount breakage debacle GM had.I will go through it carefully and look for clues.I would bet that because of the engine mount rubber separations, when GM updated/improved the engine mount design they also had to make a small design change to the frame mounts as well.This would tend to make sense as the part numbers did not change during this campaign.I will get back to you if I find anything in the 30 pages or so of GM dry reading<g>.Jim

Thanks Jim,

I was thinking the same thing about the rubber mount changes that may have something to do with it.

By the way, on one of the lower stlye mounts the part number is 3977235. This number was only on one of the mounts and not on the other side for some reason.

Also, all 4 cars had either 327's ('69) or 350's ('69 and '70) by the emblems anyway. The '70 had a 350-300 for sure when a friend of mine bought it.

Bill

Hi Bill,
That part number is a '70 number.I poured over my late '69-'70 reference material and I did find a design change that came out in Sep of '69.It is an interlocking anti-lift engine mount.It does not specifically say the frame mount was changed,but imho it easily could have.Best I can come up with. Jim

Thanks Jim.

I'm wondering why the part number changed. Aren't '69 and '70 mounts the same?

Bill

Don't know.My understanding that they are the same.The engine mounts changed in 70 to what I described in above post.We may never know for sure..... :)

About 15 years ago I changed the motor in my 70 Impala conv. from a 350 2 barrel to a 454 and I had to go to the shorter mounts. I took the 454 out of a 70 wagon & was told at the time to make sure I got the frame mounts with it.