this prob wont be enough info, im getting more tomorrow. but my friend has a (pretty sure) 92 305 RS... a guy at my work has a short block 350 just sitting.. pretty sure its from the 80s(remanufactured) how hard is it to swap a non TPI 350 into a 3rd gen?

thx
cory

 

Direct swap as far as bolt locations etc go. You will need to change a few things as far as electronics go. Since it is an RS I am assuming that it is a TBI. If so the intake will not feed the motor you will need to either modify it or get something new.

 

Everything should work with exception of maybe the heads and flexplate. They changed a lot with the SBC in the 80s, and the heads were one of them. If its an 86 or earlier, you'll need to modify the intake bolt holes on the cylinder heads so the TBI lines up. OR you could just reuse the 305 heads. They will help the low compression of the 350, but the heads suck otherwise. They will not flow, ever! You'll need to know if the rear main seal is 1 or 2 piece, as the RS currently has a 1 piece. The flexplate/flywheel is designed specifically for a 1 or 2 piece, and will not interchange.

There may be other issues, but until we know more specifics on the "mystery" 350, that's all.