well i've turboed my el falcon and blew the head gasket.and then i put a 1.3mm mls head gasket in.its al running but when i went to drive it to my tuner it started over heating so i got it home and there was massive amounts of pressure in the cooling system,what pissing out of the overflow.now i got the head machined, but i cleaned the block with a wire brush and didnt use and copper gasket as it says not to on the head gasket.is the problem with the headgasket leaking exhaust gases into the cooling system.

did you get the head tested for cracks..