Gary's 2.83:1 ring and pinion were in perfect condition at 35,000 miles. Look for ring-and-pinion gear types stamped into the gears themselves. The 2.83:1 ratio has 34 ring gear teeth and 12 pinion gear teeth. Mustangs also had 3.20:1 gears with 32 ring gear teeth and 10 pinion gear teeth. The 3.20:1 ratio is more common with three-speed manual transmission cars.