Her are my 1/2” pump/pickup tube mods done so far to the high volume low pressure oil pump.
On my setup the heads will be oiled through #2 and 4 cam journal holes as done by factory.
The crossover tube I installed will be feeding Pass. side tappet gallery and feed #1 main/rod.
Supposedly slowing down oil to allow more to get down to #3/4 mains/rods.
For information.
The crossover tube that you install is feeding the driver side from the passenger side. Which in turn is feeding the number one main and the number one rod bearing. Along with the lifters on that side.
On the oil pump pressure you keep saying high volume low pressure.
The standard 72 pump and the high-volume 72 pump use the same bypass spring.