unless you want look original, I think I would contact Edelbrock for one of their packages, heads,intake, cam, and carb.
I agree with above--if your keeping stock appearing( heads date coded ??) See what they are flowing, if they need work . Than email a reputable camshaft company with the info and they can recommend a package. Don't overlook the strength in the rotating assembly. Food for thought ,but 496 assemblies seem to be pretty popular if you need to strengthen and go the route of upgrading. Number one rule is keep everything a package. No weak links. Do your homework and research what you have. Many good websites identifying cast numbers. try: outintheshop.com
Thanks a lot.