How much boost can a stock H22 handle untuned, I was think like 5-7 psi? How much WHP could I expect out of the Greddy kit on a stock h22 with stock boost?

 

your estimations are about right to your first question. As far as your second question goes, there are too many dependents. This should answer all you questions: https://honda-tech.com/zerothread?id=316373

i found it by using the search function and typing in the words "turbo" and "prelude" since they are what come with H22s