I never did a headgasket "job" on mine, I pulled the head to replace valve seals, used a new gasket to put it back on I spiked 30+ on my hx35 when the wastegate hose popped off, didn't pop the gasket (broke ringlands I found out next day, cheap aftermarket pistons) Ran 24psi daily and constantly, including towing a station wagon up a steep as mountain, that's on the billet hx40 Never overheated or popped anything