post a couple of pictures of the front hub, and rear axle. front dust cover on the wheel bearings on 2 ton are bolted on, 1 1/2 ton screws on, similar to a pipe cap.
As Jerry said, cabs were all the same, fenders on the 1 1/2 and 2 ton were wider.
20" wheels should be 1 1/2 or 2 ton.
