Ford 9 inch Gears
The Ford 9 inch rear end also has the widest variety of ratios on the market, Particularly in the 3.0:1 to 5.0:1 range. Ford improved tooth contact of the Ford 9 inch gears by locating its pinion gear lower on the ring gear. This strengthens the whole rear end assembly. This larger offset (hypoid distance) between ring-gear and pinion-gear centerlines is the key reason the Ford is inherently stronger—but also why it’s slightly less efficient. With its 2.250-inch offset, the Ford 9 inch gears hypoid distance is greater than popular competitors, most of which are at 1.5 inches or even less.
For a Ford 9 inch rear end, swapping gears is fairly easy as it has a removable third member. It’s called a 9 inch because the ring gear measures 9 inches. The Ford 9-inch is the most desirable drag racing rear end because it has a removable carrier, which allows quick rear end changes.
Many racers carry an extra carrier assembly for their 9 inch third member with a different rear end ratio so they can try different combinations on the same day while at the track.
