Low oil pressure-72 Cutlass

[JonKrisInc]

My oil pressure gauge on my Tic Toc Tac is normally at the halfway mark when idling, and slight above that when the throttle is open. Lately, I've been hearing a slight banging noise coming from the driver's side of the engine (350) doesn't seem like a rod knock and is heavier sounding than the tap-tap I would expect from the a bad lifter. The oil pressure gauge is only at the one quarter mark when idling and just BELOW the halfway mark under throttle. I'm also hearing more of a knock when under throttle. Milton, Fred, Chris, what's happening here?       Bruce 72 Cutlass Conv. 56 Mercedes 190SL Conv. 05 Caddy STS 04 Caddy SRX