2) My overflow can/tank has a hole purposely put in the top by whomever I bought it from so they could put a bolt through to secure it down. Does this overflow tank need to be airtight? Would the radiator suck in a bunch of air if it wasn't, causing over heating?
first the overflow tank is not original...but shouldnt have much impact...I think. try it wo overflow tank hooked up, and start with water/coolant level at 3" below the neck at cool temp...
