I know of people running 14 Psi on a stock bottom end.But i wouldn't go past 12 Psi just to be safe.and 8-10 Psi is Normal.
The rule of thumb is 400-425 RWHP is the limit so if your in that ballpark with only 8-10 Psi i wouldn't go much more if you want the bottom end to stay together.
Edit: With a PI Swapped car the compression would be a tad higher (10:5:1) I believe, therefore not so good for boost but you should still be fine depending on the tune.With Boost you would have probably been better off with a set of ported NPI heads.
Yea I would watch boosting it with a PI swap ! I was going to PI swap mine but people told me better not do it with a supercharger to much compression ! But if you go threw with it post what you do and how it worked out !!