ALL BALLS starter motors are manufactured with all new components that have been fine-tuned for starting the H-D V-Twin engine All starters are supplied with a 10/32 threaded output shaft, and a conversion bolt for the earlier 1/4-20 threaded output shafts to cover all Big Twins from 1989 thru 2005 Idler gears are manufactured from cold-heated steel End frames are cold-chamber die cast and machined on precision fixtures Armature hairpins are resistance-fused to the commutator Our clutches utilize 20% oversize rollers Hitachi Starter is 5.25" overall length. Prestolite Starter is 6" overall length. Limited Lifetime Warranty NOTE: To maintain warranty All Balls Hi-Torq starters, you must run a #4 gauge battery cable set, due to the increased performance.