Destroked 41.40mm Pro R Stroker Crankshaft. Looking to get your 4cyl down to 1200cc or lower displacement, this BC destroked design will get you there. 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.