Ad4mGSR

i have a 98 GSR with 106K miles, i have the greddy kit with a spearco intercooler and 450CC injectors using uberdata. how many PSI can i run safely. all stock internals. i cannot blow the motor..this is my car for the next 4 years of my life so it must be as reliable as possible. i was thinking about running 5 PSI just to be super safe and boosted,have some power gain, i want reliablity with some power. is there a way to make the stock internal wastegate on the greddy 18G openat 5 psi or do i have to deal with 8? thanks alot