These 4.6 Fuel Rails feature huge gun-drilled 13/16” passageways and a red anodized finish. Inlet and crossover ports use 7/8-14 o-ring fittings instead of more common NPT fittings, and driver’s side rail incorporates a boss with a 1/8-27 NPT port for pressure gauge or nitrous use, while raising IPS sensor out of the flow path. We recommend using with Drake Muscle Cars line kit which includes all fittings and lines to connect to stock fuel supply line.