Story: Noangel's (Michelle) picked up an 88 K5. Previous owners wife overheated it (fan clutch wore out) and it blew the radiator hose (shut it down). Put new hose and clutch fan in and sold it to us. It idles a little rough, and I'm thinking it's a bad head gasket (or hate to say it, cracked head) due to overheating (P.O. said it ran perfect before the overheating and idles smooth as glass). A buddy of mine (mechanic) says it MAY also be an intake gasket warped from the heat sucking in air (if external leak you can find it by spraying carb clean, but if its internal it's tougher). I was wondering if I could drive this thing for a couple days to see if there are bubbles in the rad. or coolant gets low indicating head gasket or cracked head. I don't want to pull the heads if I don't have to, especially if it is just an intake gasket. My fear is if it is a head gasket or head, that the burnt antifreeze will F-up the converter. Anyone have suggestions or know if it will affect the converter or O2 sensor?