Plus one on what Don said. The Ford 302 has every conceivable part available to upgrade. It depends on budget, ability, and time. The C-4 trans also has parts available to upgrade, same limitations. What are your desires for the car? Chuck
Then, if you do all of the above, you're gonna want to upgrade your brakes. I know it's not engine work but if you want to go fast you need to be able to stop fast.