Looking at everything that was said in this thread, you have lifter collapse issues, that oil pan if memory serves is shorter in the rear than in the front, which is
not windage freindly, I am pretty sure that if you lower the oil level a couple/three quarts like electrowoman did your problem will fix itself.
Looking at the pan in the old thread from the engine build that propless sent me the link to, that windage tray is cut at an angle, which is another windage unfreindly method because the windage/turbulence pushes on one end of the oil surface and gets the oil moving in one direction causing a vortec to form in the bottom of the pan, pulling air right down to the pickup which is in the middle of the pan, (another windage unfreindly practice) the pickup should never be in the center because the swirl action of a windage issue will self center in the bottom of the pan due to the viscosity of the oil (a little like a toilet flushing).
I really need to see this resolved, I'm losing my mind

I could be full of crap, but I have been thinking of this problem a lot (too much to tell the truth)