I'm Cummins swapping a '74 Duster, thought I'd share the progress.

mbaird said
And some 2” torsion bars .
Might as well remove the windshield now vs waiting for it to jump out first time you punch it .
A 4” driveline and a minimum of a Dana 60/70 .
SS springs ( 2 passenger sides )

Reinforce the trany cross member .

lol, 2” torsion bars. You’d have to make the rear hex anchor removable so you could install the bars.

Or you could install C-body hex anchors at both ends, that would give you up to 1.5”. That’s what the NASCAR Mopars ran…