GlowShifts -4 AN Fuel Rail Thread Adapter replaces the Schrader Valve on your fuel rail and allows you to easily install your fuel pressure sender without making any major modifications to your vehicle. This adapter fits any GM 5.3 & 6.0 Fuel Rail for quick and easy monitoring of aftermarket fuel pressure sensors. Each adapter fitting is CNC-machined from billet aluminum and attaches directly to the Schrader Valve outlet on your GM factory fuel rail. The front side of the fitting also accepts a standard 1/8" NPT fitting for a direct-mount fuel gauge or a gauge sending unit. At GlowShift Gauges we back any purchase with unrivaled Customer and Tech Support.