Careful with that "High Pressure" thing. I've torn down racing engines that had a "high Pressure" pump and it grooved the main and rod bearings.
Pressure isn't needed so much as enough volume. If the engine isn't hurt, the HV pump should provide an increase in pressure as well as volume.
They tends to go hand in hand. But, if the engine is worn out and someone covered up worn parts by installing a HV pump, then all bets are off.