S&S replacement pinion gear for late 1977 - 1989 big twins in Harley-Davidson® motorcycles are carefully machined, heat treated and then finish ground. Yellow color code pinion gears measure 1.4737"-1.4745" over .105" pins for cam gears that measure 2.7344"-2.7354" over .105" pins.
Harley-Davidson® part number 24042-78.
Note: All reference to H-D® part numbers is for identification purposes only. We in no way are implying that any of S&S Cycle's products are original equipment parts or that they are equivalent to the corresponding H-D® part number shown.