That rear is a Corporate 14 bolt rear, which is a GM manufactured diff. It isn't a Dana 60. They are a very common diff found in all 3/4-1 ton chevy trucks from the early 70's to the late 90's.
The front should have a market for it granted it's actually a
Dana 44 and not a Corporate 10 bolt, that chevy switched to in the 80's as there front diff of choice.
I have a narrowed 14 bolt in the back of my CJ, and a narrowed 8-lug
Dana 44 in the front. They are tough rears that are hard to break even with v-8 power and big tires.
Most people don't use them in Jeeps since they are fricking huge and don't offer much ground clearance.
I've seen the 14 bolts in complete form go for around $350 if they have 4:10 gears or better. I've seen the 8-lug
Dana 44's also in complete form go for around $850. Good luck with the sale man.