Alot of those chevy heads are interchangable for most automotive applications, grocery getters, work trucks, the family sedan....Unless you are trying to wring every ounce of HP out of an engine you probably wouldn't notice any difference. Yes, matching heads, with equal eveything is better, but as long as the castings are simular, and the valves are the same size, those 2 CCs of chamber difference won't matter. IF you ARE trying to squeeze every bit of HP out of it, replace them both with some of the later model stuff, aftermarket angle plug 2.02s...........MP