Dana 60 rear and 44 front, huh? I'm not sure if you want to heard this, but that's the same axle setup that's under my friend's '98 1/2-ton Dodge (am I allowed to say that?).
What's more confusing is that it's a Dana 60 rear, instead of the corporate semi-floater 14-bolt that I've normally seen in 3/4 tons. Same with your dad's '83, maybe it's just me, but the only pickup applications I've heard of with 12-bolt rears are 1/2-tons.
Sorry about the rant. About the swap, if the trucks have the same wheelbase, the swap should work fine. You'll need to pluck the axles, springs and shocks, t-case, and likely driveshafts from the '76 (with all mounting parts), and install them in the '83. I don't know how involved this is, so you may have to ask someone who's done a 2WD to 4WD conversion.