HV oil pump vs Stock oil pan

I never did much wrenching on big equipment diesels, but, in the 40+ years of working on car/pickup gasoline engines, I NEVER had an engine with 10psi at idle that had all good internals. There was always something out of specs....be it oil pump, mains, rods, cam bearings, etc. This includes some freshly rebuilt engines where the crank grind didn't match the bearing size, and various assembly screwups.
I agree. Repaired a number of farm pickups with the Ford 400 and about 100k miles on them. Their oil system is the same as the Cleveland. Oil light would ficker at warm idle at stop signs, so 3 to 5 PSI. The owners would come in asking if I could put a new oil pump in for them. Drop the pan and check the pump and measure clearances. Other than a couple of minot marks, they looked good. Pull 2 an 4 main caps and push the upper shells out. Copper all around. Pull a couple of rod caps and push the upper shells out. Copper all around. Then I would look up at the timing chain and bar it back and forth to see the wear. Yup, needs a timing set also. Phone customer to let him know the situation with a price. New rod and main bearings with a double roller timing set and good to go for another 100k. A couple of guys complained that I had not replaced the oil pump. I did shim the relief spring a bit to help the bearings last. Those that complained, I suggested that they drive it for a week. If they were not happy I would charge them for a new pump and not charge to install it. Never had to do that. One the crank was worn a bit so I got .001" undersize bearings for it. The standard bearings went in the next one. All had 100k miles or a bit more.
10# at idle would be a minimum with worn bearings. A new build has a problem. 15 to 18# is OK though.
Those old Detroit 71 Series were like the Timex adverts, take a licking and just keep ticking.