Are you doing a roller cam? If not, then a standard gear is appropriate.
The HV pump pumps about 20% more possible capacity but once you reach the pressure relief point both will deliver the same oil into the engine. It will keep pressure up better at low RPM's with hot oil than the standard pump; that is of value to me. The hardened shaft never hurts.
Let me know when that machinist has some more 340's to get rid of LOL!
