Wondering if I have a blown head gasket. This is the third time I pushed antifreeze out of the reservoir. It seems to be pushing past the 16lb cap. It only happens when i am wot or pretty close to. Other than that it runs fine. It is not over filled i left it down a bit after the last time it did it. And does not loose any antifreeze other wise. 4.6l 2v built with ported P I heads comp cams Trickflow Intake. Vortech Supercharged 14lb @550 rwhp. Anything else that might cause this issue. Thanks for any input.