Here's some reference info for you. I've posted this picture on the forum before (photo #1), its one I grabbed off the internet.
Form what I read, this is a chassis cab truck with a short bed installed. It is running standard 16" dually wheels, that just barely stick out from stand fenders. The inner tire is close to the spring with this set up (see photo #2 & 3). FYI the chassis cab rear end is a 14 Bolt, not a Dana 70 like you probably have. Photo #4 is my K30 SRW with a 14 bolt, but it has 13x3.5" drums like a dually does. My drums are spaced a little further out than the Chassis cab version.
FYI 3/4 ton 14 bolts are the same as mine with a couple of differences. Drums are only 3" wide, the spring hangers are farther apart and the shock mounts are on opposite sides of the axle.
Last photo is from AMD Direct. They make 4" wider inner wheel tubs, but of course they are out of stock. They would work if you used one of the narrowed axles.
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