I have been using the polyurathane trans mount with the Th400 for a few years, but wouldn't mind trying out a GM rubber mount. I went to the dealer and grabbed the rubber 4l60e mount for 98-02 F-bodys and it wouldn't bolt up to the TH400. Should I be getting one for the 80e?

 

Bring your poly mount to autozone or the dealer and ask them to look for a matching bolt pattern

 

I deffinantly wont use a Autozone trans mount as I heard cars with 400rwhp ripping those things apart that same week they put them on. I called the dealer and asked him about the 4L80e trans mount that came on the trucks and he said its a totally different trans mount. So I guess us guys with TH400s are limited to using the polyurathane trans mounts huh.

 

Used a autozone poly mount on a 760whp SS and it held through at the track, and going on 6 months street.

Its just a store to buy poly mounts, its not "autozone brand"

 

I have used the autozone poly mount for 4+ years, the last couple of those years being with 780fts of torque..Not a single problem.
When I mentioned about the Autozone mounts, I was talking about the rubber ones, as that is what I am trying to find. A rubber mount that can work with a TH400. I have a Midwest Chassis Fab 9" setup and he recommends the stock rubber mounts to be used with it, but only problem is the stock mount doesn't bolt up to the TH400.

 

GM Makes a 1LE Mount. I will see if i can find the part number..

 

Ah. And there are the details.

 

i dont know what an F body mount looks like, but GM made a couple diff mounts for the 400-the 400 had a wider bolt spacing than 350's, and i suspect 4l60's-some of the mounts used 2 bolts and some used 1 bolt to mount to the x mem.-later they used a sloted hole for the mount, where it would fit 400's and narrower spacings
some of the sftermarket poly mounts ended up being taller than the factory spec mounts, which caused fitment problems

 

Thanks. Thats the type of info I was looking for.

 

Old post, like to know what you found... I just bought a stock one for my th400 and found what you posted... Can't afford to buy 15 mounts...

 

Shouldn't you just be able to call up GM and say:

"Hello Mr. Salesman, I would like to know if you have a transmission mount for a 1989 Chevrolet Suburban 2500 RWD(non-4x4) with the 7.4L engine?"

If you have the BMR crossmember, or any TH400 crossmember for Fbodies, it should just bolt right in, no?