ponder48

I got my 55 engine rebuilt and on the engine stand without the intake manifold or valley cover installed. I put oil in it and used a tool to spin the oil pump in hopes of getting oil up to the rockers. However, I never got any oil pressure and could see the oil flowing into the timing cover and then back into the block. Tried turning the engine, but being by myself could not run drill and turn engine at the same time. Now I have the engine in the car with valley cover and intake in place and with distributor installed. Before installing spark plugs I spun the engine for a while with no oil pressure showing (gauge was working fine before pulling engine and was showing about 40 psi after full temp came up, so pump was not replaced) and oil never came up to the rockers. Is there a chance that the pressure relief valve could be stuck open and how would the oil have been going into the timing cover? I'm hoping I don't have to pull the engine again. There is also a ball valve in the oil filter base. That part was dissembled and cleaned completely. The ball and seat both looked good.