With aftermarket 6° taper/keyway. Fits L81-85 OEM (which has no without keyway) and 70-99 aftermarket B.T. flywheels (with keyway). Sprocket shaft has keyway, use 23985-56 key (MCS 517960). Taper is 6°. Shaft is 4.262″ long from bearing shoulder to end of smalll thread. Use 24017-80 JIMS nut (MCS 978257) on flywheel side and use 24003-55 nut (MCS 517999) on sprocket side. JIMS shafts are precision machined in Camarillo, California from a special order steel. Each and every part is thoroughly inspected and after heat treating all threads go through a special process to make them withstand greater torque stress. All shafts are ground to a 16 micron finish or better, unless specified otherwise. All ground diameters are concentric to well within .0003″, making truing and rebuilding quicker and with less effort.
