Early 80's Jeep Wagoneer front axle. It is a Dana 44, with the correct bolt pattern already there. Larger disc brakes are already on it, and the steering is good to go. Just freshin' it up a bit (new wheel bearings and seals, rotors, rebuild or replace the calipers, check the carrier and pinion bearings, check the gear ratio to your current one in the rear diff, get some minor stuff welded on for the kit), and you're set. Should be able to pick up a good axle at a junkyard for about $250 (depending on if you pull it or not, U-Pull-It yards are typically a lot less).

A locker or other type of traction control device should be thought of as well, before final install. Since it's a Dana 44, a ton of aftermarket is available.