by Tom Zuloaga

We're not telling you anything you don't already know when we say that the Ford 9" rear-end is the standard differential for all levels of hot rodding and motorsports. In fact, although it is a Ford part through and through, a Ford 9-inch is common language amongst all domestic enthusiasts.

Combine this level of popularity with the reality that the factory hasn't put a leaf-spring 9-inch under a passanger car since the 70's and you have the recipe for very limited supply. For those without monetary constraints companies such as Currie, Moser and Dutchman solve the problem with newly fabricated housings. We suspect however that for those of us simply looking to add the insurance of a beefier ring and pinion a $1000 expense in housing, new axles, and ancillaries is plain out of the question.

There is a much cheaper option for those willing to do some work. Leaf-spring 9-inch housings in the 52-58" width required for Mustang, Falcons, and many others are of course the toughest to find. They've all been hoarded up a long time ago. However the too-wide variety found in trucks are still out there in many yards, and the coil spring 9-inch rears found under 70's Ford intermediates and full size cars like the T-Bird are practically free.

So here is where you get crafty. You grab one of those above mentioned niners and take your existing 8-inch rear and make yourself one nine-inch rear end. It makes perfect sense. As we'll show you here, by using your 8-inch perches and bearing ends you can salvage you existing axles. The end result is you save a bunch of cash on the housing by making it yourself. You can then put the money saved into building up the center section with the gearset ratio and traction control of your choice.

Here's our 8". The axle tubes, 28 -spline axles, brake backing plates, and brake drums will be reused. The gears were not needed, so we removed them. It measures 57- 3/8" from the outside of the axle flange to the outside of the axle flange, which is what our budget 9-inch will measure. A slightly narrower 9-inch can be built using an 8-inch from a V8 equipped Maverick or Comet. The Maverick sourced 9-inch would measure 56 1/2" wide.		This is the 9-inch housing we re-worked for the project. It is the older smooth back housing from an early 60's ford pickup. Any 9-inch housing will work, but the later large web housings will add sterngth at the expense of added un-sprung weight to the rear suspension. The 9-inch housings to look for are out of pickups from roughly 1958 to 1972 or leaf sprung Torinos, Fairlanes, Rancheros, as well as 1967-1973 Mustangs.
This shot of the 9" housing was taken to show that the housing we picked up was bent and required straightening before any work was started.		The left side axle from the 8-inch assembly measured 26-1/8". This measurement was taken by hooking the edge of the tape measure on the outside of the flange through one of the axle access holes, and measuring to the end of the splines.
The right side axle from the same assembly measured 30-1/8". The width was figured by measuring both axles as described, adding the two axle lengths together, and adding 1- 1/8". The 1-1/8" measurement is the distance between the axles, which is the same on all 8-inch and 9-inch Ford rear ends: 26-1/8" + 30-1/8" + 1-1/8" = 57-3/8"		Another important measurement we took was the the brake offset. It is the distance from the outside edge of the axle flange to the point where the brake backing plate ends up. The distance on small bearing 9-inch housing axles is 2-1/2".
The first work we did to the 9-inch housing was to cut off all the unwanted brackets. Here a plasma cutter was used to remove the old leaf spring perches. A torch will also do the trick.		A small amount of material was left to be ground down. We were careful not to remove too much material to prevent cutting into the housing.
A 4-1/2" angle grinder was used to remove the left over material.		The final finish on the axle tube was achieved with a 36 grit sanding disc on the angle grinder so that no trace of the old perches were left.

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