After a couple of weekends of hard work by myself and others, this is the payoff:
On the front axle, we swapped out from 3.21 gears to 4.56, put in an Eaton E-Locker, swapped over to chrome molly axle shafts, and welded on an Artec axle truss kit.
On the rear axle, we swapped out the same 3.21 gears to 4.56, put in an Auburn Gear ECTED limited slip/locker, and swapped chrome molly shafts.
We installed a Rubicon Express 2.5" lift kit with shocks, and put some 315/70R17 Goodyear Duratrac tires on some 17x9 Mickey Thomson Classic III wheels.
Here's what it looked like before we did all the work: