stock boost.. .the waste gate is set at 26psi. however I can roll into the throttle and keep it at 35psi stock. The TST fools the wastegate and keeps it from opening untill 35psi.

45 is the absolute MAX I would run the stocker. after that you will have what Rich described, a hole where the turbo should be.

the stock headgasket is good to 60-65psi, however the head needs to be studded around 55psi.