Chris I just went through this myself my HV pump was pushing 80 psi cold at idle and well over 100 and the relief was not sticking as I pulled the pump apart and cleaned it.
I ended up putting a standard pump in mine but before I did I put a 5w30 in it and that helped a lot ran it for a few weeks like that before I pulled and replaced the pump.
I found out a standard pump will do just fine with a little clean up and it uses less HP to turn.
My standard pump with 10w40 engine hot holds 40 psi at idle and almost 80 down track.