I agree... filters can have an effect on low oil pressure. A simple brand change can get you an increase depending on the check valve & spring pressure in them. Double-D is right (check the Fram Filter Thread). 12lbs is probably ok... I have heard the 10lbs for every 1000RPM rule too. Here is my question: why so low of pressure on a new SBC??? What kind of pan set up/oil pick-up & oil pump? It just seems a little low for a fresh engine. Not to worry- you are getting correct pressure at over 4K though. JMO Rigsby

He's pushing oil through 10 FT of hose, so that is where his low rpm pressure drop is happening. Once he spools it up the pump starts making up for it.

I agree with above 10psi per 1000 is the general rule of thumb and yours is in that range, I like more than that especially in a high performace motor but from what I gathered yours is mostly stock trim so you'll be fine.
Also have you checked the pressure with a manual guage or against another known gauge? Your gauge or sending unit could be off a tad.
And what weight oil are you using? Switching to a 20w50 will bump it up if your using a 10w40 or 5w30 oil. Just a thought.
Goodluck, Cp