I bought a 4oo years ago that was supposedly rebuilt. The oil light would come on at idle. The guy never checked or replaced the cam bearings. Even with an HV pump the light would flicker at idle in gear. I put a HP spring in the HV pump, problem solved. Cam was bouncing around in what was left of the bearings. A year later I went through the engine, new cam bearings, did it right. Not thinking I threw the same pump back on. It was after the 2nd oil filter exploded that I realized what I had done. A good used stock pump cured that. I would only consider using an HV pump if the bearing clearances were huge and if they're more than .003, then the crank needs grinding anyway.