ran 22psi with no issues in my old beantin ...
deffo get the arp bolts as normal ones wont take the strain, was running standard cam, standard shot peened rods, grs intercooler and rad, balanced bottom end, ap organic clutch (had to do a mod to the cable and add a mk5 quadrant) some hybrid turbo and the wonders of mark shead
also use the normal air box with a decent air filter but cut the front part of the top, off nasty engine bay design cone filters suck in too much hot air, i saw a real drop in air temps.. had an air charge temp sensor in the cone and throttle housing..
did many trackdays without it blowing up, kinda sorry i sold the thing really...