Hi Ted I used the same
oil pump as you but with a 100 lb spring for the relief valve. I have 100 psi cold and 35-40 psi hot at 750 rpm. at 2500 rpm 60-70 psi with a 15w-40
oil in the motor. Have a canton T oilpan and cooler. After racing the temp is 190-200f The only problem I know of having HV,HP pump is the stress on the disturbutor gear and the pushin of the cam on the front plate. I have a chromepoly shaft to spin the pump. You would have to ask the FE PROs but, the bearings are small for the FE's and the weak point. I would want all the
oil pressure and volume to the bottom of the motor. Just because the gauge saids 40 psi doesn't mean that the last rod bearing or main is getting 40 psi. You start your engine in your everyday car and it takes 3-4 second before oil is lubing all the bearing. This is why some of the guys use a accusump as a pre oiler to the motor to stop dry starts. The most damage to a motor is the first 10 seconds of start up. I wonder if the spring for your pump is only a 60 psi spring??
I would start with this first. Good luck Let us know what happens.
Rick Lake