Upgrading the fuel system without upgrading the factory rail to a larger bore or buying an after market one is pointless. The factory rail will not support 550cc inj. or a upgraded pump the pressure falls through the rail like anywhere from three to six lbs from 1 to 4 even with a fpr and fuel pressure set at 50lbs . If you want 300 hp upgrade to a better turbo wether it be toyota or mitsubishi and upgrade your fuel rail,pump and then injectors. And if you want you dont have to go with a 550cc at first , when you go with a bigger rail and a fpr with a decent pump(your turbo pump,supra pumpect.ect.) they will be more like almost 480cc or more from the increase in the flow . They will get you to your goal.Oh btw, s-afc on a 2nd is not needed. Actually it causes you get more aggressive timing from trying to lean out or add fuel by using that kind of controller. If anything get a hks vpc or a standalone if you want more capabilities .