S&S Modified 12mm CP3 Injection Pump is recommended for applications up to 1,000HP on 2001-2016 Duramax applications. For best performance use a 150 GPH or higher lift pump. This modified CP3 offers fueling capabilities up to 4,500 RPM, where a stock CP3 falls off at 3,000 RPM. Based off of an LBZ Pump and comes standard with an LBZ FPR. Custom tuning is required. No Core Fee.