Don't forget that some Sweptline 1/2 tons also had Dana 60 diff, if ordered with sure grip. These had 5 on 4 1/2" axles, not sure on the width. F100's from
~64 t0 72 also had them as an option. Put one under my 66 after hurting 3 9" diffs. About 30 years ago, saw a 68 D100 with a /6, 4 speed with a Dana 4:88.
That would be fun up to 30 MPH.