Olds 403 out, Pontiac 400 in
 

For you guys that have removed the Olds 403 from a 79 TransAm or earlier years for that matter, and put in a Pontiac 400, how does the 400 line up with the TH350 bellhousing compared to the 403? I will putting my 400 stroker into the 79 later this year and I am wondering how much adapting I will need to do. Seems unlikely that the current position of the tranny will be just right to mate with the 400 without some repositioning.

With the right engine mount brackets it's a drop in. Clam shells stay where they're at.

Bell housing and crank line stays the same
Clay

Transmission stays where it is. Everything else bolts up. Get the right Pontiac motor mounts and you will be fine. These things went down the line right next to each other and they didn't move transmissions around. That would have required way more parts, and they were trying to maximize commonality. You will need a new shaker.

Thanks guys for the info. I was hoping beyond hope that what you said would be the case. I already have the correct engine mounts for the 400 and I mounted the shaker to the hood many moons ago. I have the RPM intake and I run a 3" air box so I couldn't use the shaker in the factory position.