Will a big block fit in an '87 Trans Am?

Yes, you can do it. I've seen it done. Hooker even makes headers for 3rd gen big block swaps. For the transmission you'll need to get a new torque arm that mounts to the crossmember instead of the transmission tailshaft.

Gary

B&M used to make (they still might) a Three Speed automatic torque arm bracket for 82-92 cars. A short output TH400 should work with the bracket.

As for big blocking a 82 to 92, It has been done. Easiest way, set a bare block in place with motor mounts. Mark the mount locations, do your mounts, figure out your oil pan, then set your heads on, figure out heads vs manifolds, steering shaft, ect. Charles

I put a Pontiac 455 into an '84 Trans Am. It sat right down on the factory engine mounts. B&M makes an adapter to fit the torque arm to a TH350 or TH400, but why not build a strong TH700R4 and have an overdrive?

-rev

James Dr> Curious if I can fit a big block Chevy in my '87 Trans Am. I've heard "It

Pontiacs are small blocks though !

Rich

"Pontiacs" are NOT small blocks. Small block generally refers to a Chevrolet engine.The Pontiac V8 design differs from other manufacturer's designs in that the external dimensions of each engine, from 326 - 455 in. displacement, is identical. The displacement is determined internally with changes to the bore and stroke; therefore, there is no "big block" Pontiac engine. Pontiacs are larger than a "small block" and smaller than a "big block". However, Late model Pontiac automobiles did use the "Chevrolet small block" instead of a true Pontiac engine. Does anybody in here remember when this happened ? I bet there are a few true blue Pontiac guys in here !

There is no small/big block designation for Pontiac V8s, but put one in a 3rd gen f-body and see if you still call it a small block.

-rev

tricky wrote:

I wasn't trying to insinuate anyhting less about a pontiac 455 - just that it is the same block throughout the range ! Small ! will fit in a small block space !

Actually they are very similar in size to a 390 Ford.

Standard Shift 1980 & 1981 could be had with a SBC. From what I have seen mostly 305's. Charles

I keep hearing about Olds 307 engines in early 80's 3rd gen cars but I've never seen one.

-rev

HoDad wrote:

The 4 cylinder 3rd gens were 2.5 I-4's. Same as a S-10.

The Olds 307 was used in B&G bodies until 1987. Charles

The third gen cars did have Pontiac blocks in them... As long as you ordered your car with the 151ci Iron Duke under the hood. Just a little levity for I can see some engine discussion wars starting.

...Ron

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