This is the exhaust system for the serious racer. A true merged exhaust. Four 1 5/8" large diameter mandrel bent tubes are cut and fitted into a long merged collector. Header features thick H.D. Flanges with ground flat gasket surfaces. All internal welds are ground for true high flow performance. Includes an EMPI swivel flange racing stinger. Use the hideaway muffler or PHAT Boy to get to & from the track. Eliminates heater boxes. Type 1 only.