WARNING - These crankshafts are not balanced. Balancing required for operation. 72.5mm XP Turbo (270° pin) Stroker (+4.5mm) CNC machined from 4340 billet round bar. All cranks are stress relieved, shot peened, magna flux inspected and nitrided (multi step heat treatment) for ultimate performance. Fully profiled counterweights, rod and main journals are finish sized to work with blue or green Polaris bearings using aftermarket rods. These cranks must be fully system balanced prior to installation due to 270° offset pins.