Common Ford rear differentials include the Ford 9", the Ford 8.8", Ford 9.75" Ford 10.25" and Ford 10.5". Ford has used these differentials for a variety of vehicles from the 1950s through 2016 including Ford 'F' series trucks and 'E' series vans.
The Ford 9" and Ford 8.8" are also common differentials in rear-wheel drive Ford passenger vehicles such as the Crown Victoria and Mustang. Numerically larger differentials are typically used in heavier duty trucks such as the F250 and F350. Identify a Ford differential by the differential tag affixed to the cover of the rear differential or by using visual cues and a differential identifying tool such DiffWizard.com