What main bearings for a high performance engine?

maca said
Sorry I listed the details above. What other details will affect oil pressure. Happy to list anything else.
It's a complete standard magnum bottom end. With standard crank bearings and rods. I used to run the standard roller lifters and still had oil pressure problems but now I run solid lifters and cam.

Lifter bore wear/ excessive leakage.
If this is the motor that makes 800 horse you should tube or bush the lifter bores, and restrict cam bearing oiling. Are any oil galley plugs missing? Low oil pressure means excessive oil leakage somewhere. Was this engine rebuilt?