A Square body 73-87 GM 3/4 ton SRW may work. Depending on your wheel a spacer may be needed or not. I used a 75 chevy 3/4 ton 14 bolt in my 1946 3/4 ton. Perches will need to be moved and maybe shock location mounts. I got a 3.73 rear gearing which may be more common.
I could not use cab and chassis duals as the perches cannot be moved out on the axle enough. Maybe a full size pickup dually axle may work, dunno.
