first of all if 500hp is in your future then good flowing heads are too! Those are the essential key to making good power....Forget all about those camel backs you'll only be shooting yourself in the foot with those...AFR and Dart make good heads in the 190-200 runner styles which is where you want to be...Then and only then should you pick a cam! Your engine should be built around the basis of the head you choose....From experience 500hp from a 383 don't need 10:1 compression.....with the right combo it can be done with 9.5:1 which be easier on your wallet....

Horsepower cost money so be prepared to shell a little....If you want to be conservative build a 350hp and put a 150hp of juice to it...you'll have the best of both world this way....mellow and mean....good luck