oil pressure? slow

OK, great. I failed to observe it was in BB. What sort of gauge, that is does it use the little 1/8" nylon/ copper line? That may be plugged. The answers still apply

On a B/ RB it might pay to pull the pump and inspect the gaskets/ O ring. There's an O ring on the stem where the pump snout goes into the block, and of course a gasket between the pump/ block.

There's always a possibility the pickup tube has cracked, letting in some air.