Hot Rods GM small block 400 oil pressure problem

I think I figured mine out. Haven't fixed it yet so I am not 100% sure. Motor probably had an hour of runtime total in between cam break-in and trying to diagnose the issue. Bearings weren't terrible, but showed evidence of the issue for sure. Found damage on the rear main cap where the oil pump sits. I think I was losing pressure there. Plan to flat sand the surface and put it back together with one of those copper shim oil pump gaskets from Summit. Then I will put it back together with a new pump and a new set of bearings.

 

I have thought about using those gaskets before. It was strange to me not to use one on a SBC but I grew up on the Windsor series of SBFs that use one. I often consider it when resurrecting a Chevy engine.

 

ours was different, no bearing damage plenty of oil at rockers just no oil at sender opening

 

leave the sender out and spin up the oil pump. you can spin the pump with the oil pan off and the pick up tube in a can of oil to check where the oil loss is.