Can I swap chevy 400 trans for 350, with no modifications

[Zone_4_Lanlord]

My Pontiac originally had the 3.8 engine In it, not sure what trans. When I swapped my engine for a chevy 383 I had my trans crossmember and driveshaft modified for a 400 trans which it has now. My question is can I pull my 400 trans and swap it with a 350 with no modifications to the drive shaft or crossmember.

 

[Black Sheep]

Re: Can I swap chevy 400 trans for 350, with no modification

No

 

[Zone_4_Lanlord]

Re: Can I swap chevy 400 trans for 350, with no modification

No

What has to be done to do the swap. What's the difference in the two trans

 

[axisg]

Re: Can I swap chevy 400 trans for 350, with no modification

Couple things, if both the th350 and th400 trans are the "short" version then physically they are within 1/2" of each other in length.

- 400 mounting pad to the crossmember is about 6" further back requiring a crossmember re-work or change
- the output on a TH400 is different than the TH350 IIRC so driveshaft you have now will need another yolk put on the end

So to keep it simple grab a crossmember and driveshaft from an 84-older gbody then modify it for the dual exhaust. They mostly came with the 350c or 250c trans.
Or keep the crossmember you have and swap in a 200r4 ( the trans mounting pad for the 200r4 is almost the exact same as the th400 )

http://www.angelfire.com/fl4/pontiacdude428/transmission.html