Oil pressure problems..Help please..

[noahdallas]

I have a 350 bored .040 over with a Holley 650 douple pumper. I recently installed a new edelbrock cam/lifter set and a new timing chain. I had a couple of backfires and they have stopped thanks to working on the timing. I have some low oil pressure issues when I put the truck into drive or while idleing at a light. It starts at 40-50 psi and when I put it into gear it drops to 19-20 psi. The truck feels like it wants to die when it hits under 20 psi. Any advice would be appreciated.