WARNING - These crankshafts do not come balanced, ready to install. Balancing is required for operation. Add $200 per crank for TPR precision balance, bobweights required if using own piston and/or rod combo. 4340 billet crankshaft in stock stroke (66.2mm). MUST USE WITH SIDEWINDER OIL PUMP/SPROCKET. All cranks are stress relieved, shot peened, magna flux inspected and nitrided (multi step heat treatment) for ultimate performance. Fully profiled counterweights are designed for reduced windage through the crankcase creating less oil resistance for better rpm potential. These cranks must be fully system balanced prior to installation due various bobweights.