HV oil pump vs Stock oil pan

The oil is doing what it is supposed to do with extreme heat: drop oil pressure because it thins out with the heat.
I would fix it with oil, not stronger springs or pumps.
Try 10w/50 oil. You will get the same cold weather flow with the '10', but higher viscosity at higher temps with the 50.
I live in a moderate climate [ similar to LA ] & I use 10w/60, have done for years. Not worried about the 3.768 hp I will lose....