Personally I think hybrids are the best injector for the buck.
As for the HPOP
, it does sound like you are losing pressure. However, the reason I asked for pulsewidth is that tuning changes can also change how much oil is needed.
Here is the scenario... you're HPOP
could be weaker than normal, causing the very low ICP
that you see. Or, it could be a tuning issue, and can easily be tweaked and bring your ICP
pressures up to what you see on other trucks.
On the flip side, you do have an early 99. These came with the 15 degree HPOP
, which moves less oil than the 17 degree pumps found on the 99.5-03 PSD's. Sometimes even aftermarket singles can tax the 15 degree pump, so an Adrenaline might not be a bad idea for you.
Also when you upgrade injectors, you'll need new tuning anyway. Personally I would go with hybrids, but that's just me.