Currently building a 48 GMC 3100. The axle I have on the truck now is approximately 58 inches, but I’m having a hard time finding a Ford 9 inch that is at least close to that size. I don’t want to radius the fenders if I don’t have to, and I would like to keep a 2 1/2 inch backspace on the rims. What would be the widest axle that I could use? I have a factory assembly manual for these trucks, and I’ve yet to find any measurements for the axle.
57-59 ford cars should be close. The widest axle you can use depends on your wheels and tires and ride height. Put the wheels and tires under the truck (with the rear axle removed), get it setting right with proper clearance everywhere, and measure between the wheels, at the mating surface. That's how wide of a rearend you need.
Google 9” widths. There are charts for the drum to drum number and what they are in. 57-59 Fords along with Broncos are the narrowest then 67-up Mustangs and Fairlanes. All getting expensive now. 8.8’s are very strong but don’t have the drop out pumpkin. They are very ez to narrow and many have discs if your wanting them.
Early Bronco works. I think that the TA rear that @raven put in his '53 AD truck is about 60" he runs stock '57 Chevy wheels no problem.
The thing about doing this stuff is that you almost always can't find one with a perfect width. Then they need new bearings installed. They also need to be drilled for a Chevy bolt pattern (most likely). The costs add up. I bought 3 Ford 9" rear ends on the same day and never gave over $150 for any of them. Some people ask more and some people ask a lot more. If you are patient and haggle some, you should be able to get a complete one for $150 (or less). Narrowing the housing is easy. Do what squirrel said above and the narrow that housing to fit. Then just order new axles that already have new bearings and the correct bolt pattern. Get an Eaton geared posi unit from Summit and you are good (geared) to go.
We narrow our own. A simple jig makes it easy. A local machinist redrills them for $30 per axle. Or, the goto has long been dropping in a tri 5 rearend and you are done.
I know you are asking about a Ford axle, but I found that a 69 C10 stock 12 bolt posi axle at 62.125 inches wheel flange to wheel flange was a good substitute for the 50 GMC 100 series axle at 62.25 inches wheel flange to wheel flange. It was an easy swap and lots of ratio choices to pick from.
S10 4x4. They are 58". Lincoln Versailles 9" is 58-1/2" with the discs (which suck). If you back-convert it to drums, you lose the 1/2". Where are you located?
You do know to not use the spring pack bolt as the axle center line on this, right? It is 2" too far forward. If you use the center hole of a new spring perch, your rear wheels will not be centered in the fender opening. https://www.performanceonline.com/1947-55-Chevy-GMC-3100-Pick-Up-Rear-Leaf-Spring-Axle-Seats/
1990-1992 Ford Ranger 8.8-Inch Axle – 56.50 inches 1993-2009 Ford Ranger 8.8-inch Axle – 58.50 inches 1991-2003 Ford Explorer 8.8-Inch Axle – 59.625 inches
you want at least 61 inches unless you plan to run deep reverse wheels. A 74 Nova rear end at 60 inches won't let you run a stock 15 inch Chevy steel wheel on the back without rubbing and yes I can go out tomorrow and take photos if there are non believers. I carried a stock 15 inch 5 bolt Chevy wheel for a spare for a while until I had a flat on the rear and had to swap one of the front wheels to the rear and put the spare on the front to limp in to the tire store. A chrome reverse wheel gave me the clearance that I needed to clear the bed side. I don't have a 48/54 torque tube rear end out here but I have a 55 3100 rear end that I can measure in the morning and I think it is 61 wms to wms.
60-61 inch wms to wms is what works best on the AD trucks....then you can run 8 inchwide rear wheels with 3 1/2' backspace
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