if using hondata the stock fpr is fine. it is vacum/boost dependant, and the injector pulse is what will control your fuel at a given rpm. I ran 10 psi on my b16, with 450cc, stock fpr and the walbro 255lph hp. it idle'd like it was stock and I still got 28mpg in city, so the ability to control the fuel is great. depending on how much spray you may want the hp, it may be over kill, but I'd rather have too much and have to manage it down a notch than not enough, cause you can't use a management system to give more fuel than the pump will give.