If you want to add more pressure, the HV pump is not the way to do it. Get the MP high pressure spring and put it in the pump you have. But 15 PSI at 800 RPM hot is plenty. If you don't think it is, unscrew the filter while it's running.
Rusty I was advised by a Tech at Melling that the high pressure spring wont gain any more pressure at idle as the relief valve controlled by the spring is closed at idle. He recommended I install the HV oil pump to gain psi at idle.
It's the roller lifters using some extra oil causing a small pressure drop.
With flat tappet lifters this same pump produced 25 psi @ hot idle
