72.5mm XP Turbo (270° pin) Stroker (+4.5mm) - This crank comes fully system balanced to customer bobweight specifications. 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 are fully system balanced to the following bobweight: