Bolt-in for stock 883/1200 models, designed for 883/1200 conversion kits. +5 HP & +2ft-lb torque, over stock 1200, with S&S air cleaner & slip-on mufflers, from 3500RPM up. Note: Requires cam lobe clearancing in stock crankcases. Note: Will fit 91-99 XL models when 00-20 style pinion gear (OEM 24047-00) is installed to match the pitch on the second cam. Note: 00-03 XL with S&S flywheels or pinion shafts require 91-99 style cams and S&S 86-87 pinion gear & oil pump drive gear.