ok i just bought a 89 firebird and it has a 2.8l with a spin bearing in it. im thinking about putting a 350 in it. but ive been told by some people that the frame was altered on the 2.8l firebirds. im looking to stay with a TPI motor. but i also have a small block 400 that i could use and dont know if it will fit. im just wondering what kind of changes i will have to do (I have a 4.3l TBI motor that could also be a canidate for fuel purposes)

edit: i also have a 700r4 to be used as a transmission.

 

well the outside dimensions of sbc's are all the same so you'd need the same thing for the 350 as you would the 400.

As for the frames being alterd i'm pretty sure they are the same (unibody anyways). You will want subframe connecters at the least. I'd probably do more major modification if it were me but, most seem to be fine with sfc's.

As for the 700r4 it wasn't off of the v6 was it? If so i don't think you can use it, may be wrong though.

Btw if you plan to run any sorta sticky tires slicks or such be gentle on the tranny, it won't be able to take major abuse without a major rebuild.

As for the rearend it will be either a 9 bolt or a 10 bolt, both are up to the task of standing behind a moderate 350 or 400 as long as you aren't running slicks.

Well that's about all the info i have good luck with the swap.

 

the 700r4 was out of a full size van. and i dont plan on running slicks. and as far as i know the tranny in there now wount bolt up ot a 4.3 a 350 or 400 which is why i brought up the 700r4 and im fairly sure it has a 10 bolt on it

 

The differences between V6 cars and V8 cars are listed in the V6 to V8 swap sticky above.