Many years ago I was doing re-ring jobs pretty regularly.
These were low buck deals on high mileage engines.
Most were BB Mopars.
Unless there was a real problem with the crank, they got polished and new bearings.
Several had well over 100k on them when the re-ring job happened.

Those things always had plenty of oil pressure........50-ish going down the road.

I’d pull the oil pump off and apart and check the clearances.
If it’s good, try the HP spring in it.

If that doesn’t help...... there’s probably just a lot of “leaks” in the motor.

I’ve seen big chunks of babbit missing from the cam bearings on old stock engines.