low oil pressure

DARTLARRY said
stock LA360 with a small cam, and headers. The oil pressure when cold is never over 45psi, when warm it is at near zero. I replaced oil with 20w50, in hopes that it would increase some pressure, it may be 10psi when warm now, still never increases above 45psi no matter the rpm. Next step replace oil pump, if the bearing clearances are creating the issue I don't want to pull pan in car and change pump. Ay thoughts?

As said confirm the readings first with another gauge. If the readings are accurate, and the pressures never exceed 45 psi regardless of RPM, then it is very probably the pump.

BTW, there are 2 relief spring pressures: one at 55 psi and one around 72 psi. So you could have the lower pressure spring and a -10 psi error in your gauge across the range, and both the pump and bearings be A-OK.