440 Oil Pressure Issues..

Sounds like maybe high bearing clearance? Something is up. I'm inclined to agree with Brian6pac. Get an 1/8" nipple and a 1/8 x 1/4" bell reducer, 1/4" x hose barb fitting and some clear vinyl tubing. Assemble and tee it into the spare pressure port at the back of the block, run the other end of the tube into the valve cover fill. Have the car warmed up fully, oil hot. Pull the intermediate shaft again and run the pump with a priming shaft, look for bubbles in the clear tube while oil flows back into the valve cover.