Brakes would be the same but you'll need entirely new exhaust system. The frame will be fine unless you decide to go more than GM had intended. IIRC the springs might need to be changed but some transmissions should bolt up and the rear ends were the same. If you have a Sprint the 3:55 rear end might be a peg leg but is a nice gear for a street machine.

What car and OHC do you have and where are you in Texas?