Compatible with LS1/LS6 equipped with FAST® LSX Intake Manifold.; The FAST® High Flow Billet Fuel Rails feature a larger internal diameter that dampens the pulses and provides increased fuel volume, ensuring that your injectors never run dry. In addition, they yield better fuel distribution and ultimately greater horsepower. Featuring high strength billet, lightweight, black anodized aluminum construction, FAST® fuel rails deliver performance in addition to a show car quality appearance.;.