Very stubron head gasket
Reminds me of a time when a freind of mine tried to take a head off with a bolt still bolting the head down. Try and try he may have done to the tune of sweat pooring of his head he did. LOL!
I have in the passed have very stubborn gacskets. Try this;
With a gasket scraper and a small ball peen hammer, tap tap tap away. Take your time. I had to do this last time arond myself.