This is the Raptor-4G fuel system for the 6.6L Duramax. This system mounts to the frame rail using the supplied sandwich plate mounting system. The suction line connects to the factory suction fitting on top of the fuel module. The pressure side connects to the factory injection pump feed line on the frame back by the fuel cooler. These pumps are internally regulated and do not require a return line. Check out our installation manual for a list of parts that are included with this kit.