Andrews "final belt drive" transmission belt pulleys match the 1994 to present design with a 50% longer internal spline engagement length than the earlier design. For 1985 thru 1993 models Andrews pulleys may need a 33334-85 modified spacer for correct fit on some models Stock equipment on all 5 Speed Big Twins is a 32 tooth pulley. The 34 tooth pulley will reduce engine RPM with 6% for smoother cruising.
Note: Although 2000 and later models use a narrower (1 1/8" in stead of 1 1/2") final belt and rear pulley, the front pulley width has remained unchanged and will also fit Twin Cam models.