Well if we're all going to boost more, it's hightly recommended that we upgrade valvetrain. Right now budget is my problem, just got laid off, got enough to tune my car but not get valvetrains, i've heard many guys doing 15 psi and more on a bone stock head, right now im at 8 psi with built bottom but bone stock head, i'm going to tune it with a gt35r and i want to do 13 or 14 psi, you guys think it'll be safe with stock valvetrain?