The factory GT500 fuel system is good for 700 or so horsepower at the rear wheels if you install bigger injectors. As you start pushing past 800 rwhp and beyond, it's time to look at a whole system. Lethal worked with Fore Precision Works to create a complete triple-pump fuel system, in return and returnless variants, for S197 Mustangs. The heart of the system is this Fore billet, three-pump, return-style hat (PN FPW-0036-500; $440). It houses three Walbro GSS342 pumps, which move 255 liters per hour each!