I was talking to one of the drivers that come into work tonight, and we were talking about cars, and heads and such came up. I was curious if our engines are mostly cast or aluminum? (Sorry I havent dug into it much other than fluids and plugs). We were talking about the polished fastman TB and he was saying how porus the cast engine blocks are and how much of a diff it makes if the walls are polished as far as HP.