This is the AirDog II-4G DF-165 fuel system for the 1999-2003 7.3L Powerstroke. This replaces the factory frame rail fuel pump. This system mounts to the frame rail using the supplied sandwich plate mounting system. The suction side hooks up to the factory suction line on the frame rail. The pressure side connects to the factory feed line to the injection pump. The AirDog Air/Vapor return is sent back to the tank through a filler neck return tee. This is a 165GPH (Gallon Per Hour) fuel system for moderately modified trucks.