Bersaglieri

Well I before the cam install my oil pressure was being weird, staying between 35-40psi through all RPM's. I figured it was just a dirty filter. Now after the cam install the PSI is about 30 at idle, 40-42 while driving, and 42-45 at WOT up to 6k. Does anyone have any suggestions? I went back to be old oil and oil filter combo [0w30 Castrol Syntec/AC Delco 1218] and its still the same. Any suggestions on what to look for? Would a leak cause the psi to stay lower? How about a lose dipstick? I'm hoping its not my bottom end taking a dump or a head gasket, but if it is, I guess its already time for bigger and better.

-Dustin-