When it came time to replace the closed-drive axle in my '49 Chevy-Project Purple Pig-I wanted a rearend that was strong, compact, and had brakes that would be more than accurate for the increased horsepower. Currie Enterprises put together a new 8-inch Ford axle for us, with 11-inch drum brakes, and an offset pumpkin so that the driveshaft runs straight. I went for an 8-inch over a 9-inch, owing to its smaller pumpkin as there will be limited room under the Chevy once the suspension is on full drop with the chassis C-notch, and I still have to run an exhaust system over the axle. Plus, the 8-inch is plenty strong enough for a street car.
Here's what we started with: a pair of Torino-type axle housing ends, a pair of 3 x 0.188-inch wall DOM tubes, and a stock Ford 8-inch axle centersection. This had the original axle tubes cut off and turned down so the new 3-inch ones would slide over them.
While I'm sure only a limited number of you are going to undertake narrowing your own axle casings, it's nice to see how it's done. Having said that, it's not that hard of a job and Currie even sells an assembly alignment bar under its Nine-Plus brand (www.new9inch.com), which sells brand-new 9-inch rearend components, offering everything from gear cases and mini-spools to T-bolts, bearings, gaskets, and retainer plates. If you own a lathe you could even turn up your own collars for an alignment bar.
Seeing as I mentioned retainer plates, the 9-inch Ford axles are often described as having large [or Torino] bearings. This simply relates to early and late bearings respectively, with the earlier style having a larger bolt pattern on its housing ends, and subsequently the bearing retainer plates.
Ford 8-inch axles all came as standard with 2 3/4-inch axle tubes, usually tapering down to 2 1/2 inches at the ends, and small axle bearings. The main advantage of the 8-inch rearend Currie Enterprises fabricated for us is that the axle tubes were replaced with 3-inch tubes-meaning aftermarket axle brackets such as those for ladder bars or four-links-will fit easily, though we didn't require that facility, and it now features the larger Torino axle bearings and housing ends, allowing the fitment of 11-inch brakes-a huge improvement both aesthetically and functionally.
While the 11-inch drum brakes will likely be sufficient for our Chevy, it's good to know that these all-new brake kits use the Aftermarket Brake Configuration Standard (ABCS), which was developed to provide interchangeability. Any axle that uses Torino housing ends, 2.8-inch register (the diameter of the hole in the center of the drum) and 2 1/2-inch brake space (the distance from the outside of the housing end to the outside of the axle flange with the axle installed) can use any ABCS-configured disc or drum brake kit with no modifications. These include 11-inch Explorer and 11 5/8-inch Mustang discs, as well as Baer, Wilwood, and SSBC discs. This means a swap to discs if required at a later date will be a bolt-in swap!
