stu ive been running the set up that mark shead done for my 225 chip he done a couple of fuel mods ive got the grs cooler stg3 head plus other stuff, but my piston skirts have pushed in, i think they were cheap new ones they were +.5 and i had 1.5 mm skimmed off of the top . i was running about 20/22psi on boost, now i want to put in a standard block and pistons will it be safe to run about 18 psi .

cheers