Fits: 4BT 3.9l Cummins Engines with P7100 P-Pump *Note: 14mm fittings on each end *Note: Will not fit engines with 12mm injectors, 12mm pump outlet, engines with A-pumps, or VE Rotary style pumps. Tip: 12mm thread injectors use a 17mm wrench for line nut and 14mm thread injectors use a 19mm wrench for line nut.