Replaces the original flywheels in S&S® 124'' V124 engine for '84-'99 Big TwinPinion and sprocket shafts are forged as part of the flywheelThe only joints in the assembly are where the 1.671'' diameter connecting rod crankpin is pressed into the flywheelsCNC machined from heat-treated, closed die, steel forgings, which are 114% stronger than late style stock steel flywheelsFully assembled with premium quaility S&S® heavy duty 7.667'' connecting rods, with full width wrist pin ends, and dynamically balancedAssembly is trued to less than .0005'' runout on pinion and sprocket shaft bearing surfaces, making them capable of higher rpmThree piece designLeft side flywheel is notched for crank position sensor.Balanced for S&S stock bore and 3-5/8'' stroker pistons.