Depends on what oil pump is on it. If it has a stock pump, then probably 15 psi or so at hot idle and 40+ at speed.
A high volume pump will be at least 20 psi hot idle and 60+ at speed. Of course this can vary if someone has messed w/ the relief spring and/or bearing clearances.

Checking your timing is another way to easily see if they balancer has slipped. If the timing light is telling you the timing is different now than where you previously set it...it's time to get #1 at true TDC and verify the timing mark.