This direct fit bolt on upgraded HPOP is perfect for moderate to extreme upgraded engines. Our Adrenaline Heavy Duty version - this high Output Version was first introduced built in the stock housings and has been running in trucks since April of 2009. It will be an improvement in performance over your stock pump for stock or larger injectors. We have had great success feeding any injector size from stock up to a conventional 270cc and 300+cc hybrid injectors.