DD, a suggestion on aluminum head purchase. Consider "calling" and talking to whichever company you're "thinking" of purchasing from, talk to Tech Support and tell them about your car, have weight, engine (and what its present set up is), carb, headers, rear ratio, trans information (and if you know stall on converter). Let them know your intended type of driving. I "highly recommend" purchasing a "already figured out" kit (cam, fully built heads, etc.), from them. Listen to what they suggest, they've already done testing and engineering to find best combinations for what you have and intended use. Now, if you already have a good intake, carb & ignition system you can (and ask them if what you have will work "well" for their kit) just get their heads, cam & lifters. Just my thoughts as if you only buy heads your present cam, intake, ignition & carb may be a big disappointment to you. Kits are already figured out for applications. Just my thoughts.