Oswald - Below are a bunch of screenshots of relevant info from the GM Heritage Centers
1954 Chevrolet Truck Data PDF that provide some info about the single vs dual wheel setup for your '54 3600.
The data doesn't show any difference in the rear brakes from single to dual wheel applications, but does show the dual wheels dimensions are significantly different from the standard single wheel setup. Huge difference in offset from 1/8" for standard 15" single wheels to 4-9/16" for dual 16" wheels (including the front wheels).
A check of Chevy Master Parts Books would point out if there where differences in stud lengths and any other related pieces that may be involved in the dual wheel install. I think IIRC, the front wheel hub are different to place the 4-9/16" wheel offset in the correct place for proper steering geometry, but need to also check the parts books to confirm if true or not.
More to come when I get a chance to do some Parts Book research.
