1957 to 1986 Ford rear end widths
1/1/2026
Original credit to Dave_C and the Fordnatics mailing list - original data from https://mustangsandmore.com/ubb/FordRearDimensions.html
This list provides flange-to-flange measurements for Ford rear ends.
Note: These measurements are from flange to flange. Subtract 5" for bare housing length.
Axle Width Reference (Flange to Flange)
| Vehicle Application | Width (Inches) | Notes |
|---|---|---|
| 57-59 Ranchero & Station Wagon | 57.25" | Narrowest 9" housing |
| 64 Falcon | 58.00" | |
| 65-66 Mustang | 57.25" | |
| 66-77 Bronco (9") | 58.00" | 5-on-5 1/2" bolt circle |
| 67 Cougar | 60.00" | |
| 67 Fairlane | 63.50" | |
| 67-70 Mustang | 59.25" | |
| 67-71 Comet, Cougar, Mustang, Fairlane | 59.25" | |
| 67-73 Mustang, Torino, Ranchero, Fairlane (9") | 59.25" - 61.25" | |
| 71-73 Mustang | 61.25" | |
| 72 Ford Van (3/4 ton) | 68.00" | |
| 73-86 Ford Trucks | 65.25" | |
| 74 Maverick (8") | 56.50" | |
| 75 Mustang II (8") | 57.00" | |
| 77-81 Granada/Versailles | 58.00" | |
| 77-81 Versailles | 58.50" |
The Ford 9" Rear Axle
Where to Find Them
- 67-73 Mustangs & Cougars: Medium and big block models.
- 66-71 Intermediates: Fairlanes, Torinos, Montegos, Comets (with big blocks).
- 57-59 Full Size: V8 Fords and Mercurys.
- 77-81 Models: Lincoln Versailles and various Trucks.
Housing Types
- Light Duty: (67-73 Mustang/Cougar) Thinnest housing material, small axle bearings, 28 and 31 splines.
- Medium Duty: (57-68 passenger car and 1/2 ton truck) Stronger than Mustang type, 28 and 31 splines.
- Heavy Duty: (Ranchero/Torino) Thick wall housing, 3.25" diameter axle tubes with flat tops.
- Extra Heavy Duty: (69-77 Galaxies/Lincolns/Late Pickups) 3.25" diameter all the way to the backing plate. Coil housings have upper control arm mounts.
Identifying Housing Centers
- 1957: No dimples, flat center band up the center of the rear cover, bottom drain plug.
- 1958-59: Two dimples on back of housing, flat center band, some had drain holes.
- 1960-67: Two dimples, flat center band, oil level hole in back cover.
- 1963-77 (9.375" Centers): Found in Lincoln, LTD, T-Birds. Housings cut away at gasket surface for ring gear clearance; one curved rib at front top. Note: Strong, but no aftermarket gears available.
Axle Shafts & Splines
-
28 Spline: Most are tapered and cannot be shortened.
- Exception: 69-73 Mustang and Cougars have straight 28 spline axles that can be modified.
-
31 Spline: 1972 and earlier versions can typically be shortened and resplined.
-
73-Later (Big Cars): Feature a 5-on-5 bolt circle; these axles cannot be shortened.
67-73 Mustang Identification (by wheel flange)
- Oval Hole: 28 splines.
- Two large holes & countersunk center: 31 splines.