4th Main Drive Gear. Fits 4Spd Big Twin 1977-1986. - Andrews Products Seat & S/bar accessories-all models * Performance air filter is

* Performance air filter is made from high-flow black pre-oiled cotton media

* Wind-tunnel and real world tested

* Also Retro Fits Radical Radius pipes originally supplied with 2 separate Mufflers

* Made Out Of High Strength 4140 Tool Steel

* Easy bolt-on replacement for models with stock oil cooler system

4th Main Drive Gear. Fits 4Spd Big Twin 1977-1986. - Andrews Products Seat & S/bar accessories-all models * Performance air filter isStock main drive gear (4TH) 26 Teeth. * (1977 1986) (caged rollar) OEM 35067 77 & OEM 35067 84 * Replacement 4th gears are made with wider drive slots and steeper lead in ramps for more positive 3 4 shifting. * The O ring groove is a design update for all chain drive 4th gears from 1977 through 1986.