I've been contemplating the 8 lug disc for my 54 also. I've been to the auto parts store and found that a disc from a 98 and up Chevy 4X4 will slip over the top of your existing hub. The next step is a caliper and bracket. I'm sure it wouldn't be too hard to find an appropriate size caliper, but the bracket, you'll have to find someone with a plasma torch or CNC to do some fabricating. If you go to
www.TSMMFG.COM they have a rear 8 lug kit for the Eaton axles, they may be able to do something for the front.
