I was working on this for my 3/4 ton, but got side-tracked. If you go with a modern 16" wheel, the setback on the wheel is about 2" deeper than stock on these old trucks. I can't recall the numbers right now, but a 14 bolt full floater out of a 3/4 ton pickup combined with the newer wheels should come out about an inch to wide for the pickup with the axle moved back 1 to 1-1/2 inches. I need to get back and check, but the man I was talking with thought we could swap around brake drums and find a solution. Also, the 12 bolt rear was a bit narrower. I checked a late model van, the differential was even wider. I don't know if there is a difference in width between your panel and a pickup. Also, I was told that the newer trucks have a 3.42 gear instead of the 3.73 that was common in the late 80's.
