Thread: GMC block vs Chevy block

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I pulled my woren out 350 out of my 76 gmc pickup and am trying to put my 400 in it but the motor mounts are about 1 inch back and the tranny is bolted to it so its back all the way i was wondering if there was any diffrences in the blocks or if any one has an idea of whats going on.

Shouldn't be unless someone has stuck a Buick, Olds, or Pontiac motor in there. Is the tranny's bell housing bolt pattern a BOP pattern or is it a Chevy pattern? There are also adapters that will mate a Chevy motor to a BOP tranny as well.

Does the tranny have the short tail shaft instead of the long one??

The engine blocks should be the same,the difference is probably in your trans mount. If you are using the original trans,and just a new engine, I don't know why it's an inch off,but no big deal,just move the frame brackets. Hank

Your post is a bi cryptic.

The transmission mounts are different for a th350 and th400 transmissions.

If you have not changed the transmission or trans mounts- I suspect that you have the engine mount brackets on incorrectly.