I havnt done a leak down on the heads and I dont know if they are warped. Either way if thats the problem what should I do because I want to keep all of my heads internals. My heads were very quite they didnt make any tapping noises. I need a blueprint of where i should go from here. Where do I get used heads from, whats the chances of my heads being warped versus being cracked, where can I buy used heads from. Warped can be fixed but cracked will have to be replaced. I want the least expensive smartest route.