The '72 is, in my opinion, the worst possible 429/460 to start with if you want to make any power. The heads were open chamber ('72 only, Ford went back to closed chamber for '73 because the open chambers were so awful) and extremely retarded cam timing was used. '72 was the first year into the Arab Oil Embargo and all the manufacturers were rating the motors at net hp while using every option available to them to clean up the motors for federal emissions guidelines and "cat-piss" unleaded fuel.