72bluNblu said

There's only 2 manufacturers of the 2" drop spindles. The Fatman spindles are constructed, they're welded together. The Magnumforce/PST/Firm Feel drop spindles are all the same. Magnumforce was the first to offer them, but I doubt they're the actual manufacturer.

The caliper position is different between the Magnumforce 2" drop spindles and a standard spindle, and the neck on the spindle is different as well. The caliper bracket clearance may be the issue. You can use stock caliper brackets on the 2" drop spindles, I did when I had them. But you can see the location of the caliper is different, the stock spindles put the caliper at like 10 or 2 o'clock depending on which side you have them on, the MF 2" drop spindles put them at more like 9 or 3.

Reproduction stock spindle
View attachment 1715597279
Drop spindle- also notice the difference in the shape of the "face" of the spindle
View attachment 1715597280

With the 11.75" caliper brackets and caliper - you can see the caliper is basically vertical
View attachment 1715597278

Not my picture, but you can see the caliper is more at more like the 10 o'clock position
View attachment 1715597285

VS the drop spindle, which has it right at 9
View attachment 1715597277

The caliper brackets are the difference in the Wilwood kits as well
140-15468 (stock spindle)
View attachment 1715597286

140-11547 (drop spindle)
View attachment 1715597287

Whether or not they work with the Strange caliper brackets I have no idea. The stock caliper brackets are all sliders too, so if the thickness is off a little on the mounting area on the spindle it doesn't matter much. The Strange and Wilwood calipers are fixed, so you may also need to space them to make them align correctly because the spindle may not be the same thickness at the caliper bracket mounts.


The drop spindles move the track width the exact same amount as the '73+ BBP pattern disks, that part of the geometry is the same. The biggest difference is the location of the axle stub with regard to the ball joints and steering arms. The tie rod end clearance is really only a big issue if you were planning on larger diameter rims. With 15's the backspace limits are about the same because the tie rod ends are the limiting clearance, it's the ball joints/brakes/suspension. Basically you're not going to run much more than 4.5" to 4.75" of backspace on a 15" rim, and that's pretty much true with either spindle.

The difference is with the larger diameter rims. A 17" rim clears the ball joints and control arms with a stock spindle, so you can run more backspace until the tie rod ends limit you around 5.6" or 5.7" on most rims. With 18" rims not even the tie rod ends are an issue with stock spindles. But with drop spindles, that steering arm is moving 2" with respect to the center of the wheel. Which makes your rim clearance more like a 15" rim. So you don't get to run a big backspace with the larger diameter rim anymore. I was able to run a 17x9 with 5" of backspace when I was running the 2" drop spindles, but that was totally maxed out on tie rod clearance. That was on my Challenger, you'd need more backspace to fit a 9" on an A-body but the 5" backspace limit would be about the same. It's a little better than what you could do with 15's and stock spindles, but no where near what you can usually do with stock spindles and 17's or 18's.

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