I do know that from 1960-1972 Chevrolet had 6 lug 2WD trucks that had IFS.
In '71 and '72 and later the only 6-lug trucks were 4wd. Starting in '71 the 1/2-ton trucks were all 5-lug with disk brakes.
'60 to '62 have the torsion bar suspension that would be hard to adapt.
The '63 to '70 drum brake IFS is really too wide to fit under an AD truck, though people have narrowed them and used offset wheels to make it work.
