Oil Pressure Very low on new setup!!!

[Z28EATR]

ok i have searched past threads and got some good advice but i was hoping some of the guru's on here could maybe help with my particular issue. Ok i have a 331 stroker motor with all new everything!!! The pump is a melling standard pressure, standard volume. However when i got the pump the guy also sold me a kit with a new knockout plug and a 1\8th inch aluminum spacer that goes in between the spring and plug that gives the pump an extra 10 psi of pressure. So the new motor has 3000 miles on it and it is now showing really low oil pressure after it warms up. The old stock gauge wouldnt even read at idle so i bought a mechanical and installed it. Well when cold the pressure at idle is 60+ but as the car starts to warm up it drops off and when i ran it down the road it runs in between 30-40 and if i step into it, it will peak at 60. So i get back to the house and let it idle and the pressure drops to 10 psi @ 650 rpms. Yes it idles down really low. So if i rev it up a little the pressure will go up to about 30 @ 2500 rpms and if i tach it up to 4500 or higher it will again spike at 60. When the car is idleing at 650 rpms and the pressure is really low but i DONT get any chatter out of the valvetrain which i figured i probably would if the pump was defective. Please guys, any help is greatly appreciated. Is this normal? If you need more details on my setup check out my mod list.