2.02" intake valve heads were the ones guys would fight over, used to hear them called "fuelie" heads. compression is good for power, but with todays crappy gas, and lower octanes, not so good. There were single hump (power pack) and double hump (camel back), and I think at least 2 versions of the latter? I'm sorry, going only from memory, likely wrong on all of my thoughts and need to leave comments to others who definately know before I muddy your water any....