My engine builder was adamant about not using a high volume pump on my stroker, claiming in this application it is unnecessary. We used a melling stock pump that was clearance checked, and shimmed as I recall. He told me the high volume pumps put unnecessary load on oil pump drive shaft, and proper clearances in engine will maintain good pressure with stock blueprinted pump. I run 05-30 royal purple oil. After everything is well heated on a highway drive mine settles in at 62-64 PSI, with a hot idle of 26-30.
It is my understanding that the high volume pumps actually do not pump higher volume, but increase the pressure. This is because the galleys in the engine cant actually accommodate higher volumes and so pressure backs up. So you end up unnecessarily putting more effort into turning the pump, with no benefit.
Again, this is what I have been told and I trust my engine builders words.
I do not believe this an oil pressure issue though. Regardless of pump you chose, many run high volume pumps with no leaking issues.
