440 build for a tow rig/"muscle" truck?

R&D,
If you want to improve the oil system on a BB, work on the inlet side of the pump. The outlet side will then have more idle pressure because you have made the pump more efficient.
The inlet side has a long, small diam pick up with tight corners inside the block for the oil to negotiate it's way into the pump inlet. Fit a larger Hemi pick up & enlarge the two inlet holes in the block, as per the MP bulletins. Where the pump body bolts to the block, remove/smooth/radius any overhanging bits on both the inlet & outlet sides of the pump.