I talked to a coworker and apparently the fuel trims should be able to compensate for the pressure difference. Also a proper dyno tune should negate the issue. I still want to fix the pressure though. The jet pump came with 2 other size restrictors. I may drill one out till it doesn't cause the back pressure. I currently have bigger issues so it's going on the back burner.Sounds like you are diagnosing the fuel over-pressure situation. That’s pretty high fuel pressure! If it ends up being the siphon pump how will you fix it? Can you drill it out or make a bypass to route some fuel around it?