bo-at ??\'s hey all -- I have a 94 ski boat with a chevy 350 I/O weber quadra jet. As far as I can find, it has automotive "stock" heads on it with a lopey cam in it. The exhaust system, iggy, alternator, and external cooling system are all screwy marine stuff though... It's a 1994 mercruiser 5.7 I/O alpha I gen 2 (250hp) btw. a few questions. (1) how much performance gain could I get out of slapping new heads on her? (2) are "automotive" heads marine compatable? (3) do k&n filters count as spark-arresting? any thoughts or prognostications appreciated.