how high can you go?

[hkssupra]

hello everyone, new to forum, i have a 87 supra that i have been working on for quite a while now, i just recently drove it for the first time and when i hit full boost, i was only at 5-6 lbs. the car has a manual bc, do you think possibly it could be bad? i had it turned up to about 10-15 lbs, i know its not my charge pipes or vacuum leaks so this is the only thing left i can think of. Also i was wondering how high i can boost safely. the car has- hks f-con,fcd, stock pipes and intercooler, hks bov, and straight threw exhaust(hollow cats) and greddy muffler. what psi do you think ill be safe running? any help is appreciated..thanks