Stock specs, everything in order.

Common Design

All MJs were built as a full unibody design with the body and frame rails tied/welded together as one piece and cannot be removed, however, the rear is a fully boxed frame with the bed bolted to it, making the bed removable. All MJs have solid axles front and rear. The suspension consists of coils for the front and leaf springs for the rear. All MJs came with disc brakes in the front and drums in the rear.

Also, all MJ's through all years are equipped with a height sensing proportioning valve that is used to change the bias of the brakes if the bed had a load in it.

For those curious to the differences in Cherokee's and Comanche's:

The taillight lenses are different from a Cherokee's, the wheel flares are the same (as a 2dr Cherokee), the front doors off of 4-door XJ's (84-92 at least) are swappable, hoods are swappable from 84-92 models Cherokee's (Cherokee's above 92 used spring-loaded hinges), and all mechanical/electronic parts forward of the firewall ARE identical.

Body

The body comes only in standard cab model with a rear double-top hatch tailgate. Comes in longbed or shortbeds two-tone versions. Long bed versions come with a larger gas tank than the short bed and is located front of the axle. Short bed version was not avaiable in 1986.

Interior: door panels are removable as stock. Bench seats and bucket seats DO NOT have the same mounting brackets as XJ seats, but are fairly easy to make fit. gauge cluster is removed by 4 screws. gauge cluster during 86' have mechanical-powered gauges. On 87-90 gauges, The speedometer uses a cable, but all gauges 91-92 use a computer cable.

Wheelbase:

short bed 2wd=113.1 4wd=112.9 (18 gal tank)
long bed 2wd=119.6 4wd=119.4 (16 gal [longbed, opt shortbed] 23.5 gal [opt longbed; standard from 1989])

Engines

2.5L I4 TBI (fuel injected) - 117 hp @ 5000 rpm, 135 ftlb @ 3500 rpm - used in 86 and updated in 87-90 to 121hp (2.5L became MPI in 91 and was rated for 130hp @ 5250 and 149 ftlb @ 3250) --- Fuel Miser package was available, lowering the HP
to 100hp and included a 4 speed manual trans, no tail gate, undercoating, and 3.31 axle gears. the 4x4 Miser got the same treatment as well as no spare tire or brackets.

The "Metric Tonne" or "Big Ton" or "payload package" was designed for hauling, was only available on longbeds, and consisted of an AMC-20 rear axle in 86, Dana 44 rear axle in 87-92, heavier duty springs front and rear, tougher shocks, the larger tires, fullsize spare and 15x7 wheels. In the AMC-20, the only gear ratio was 4.10, Dana 44s got stuck with the standard ratio available with the specified drivetrain combo (3.08 for 4.0l/manual, 3.54 for 4.0l/autos, and 4.09 for 2.5l/manuals).

Actually, there were 2 different styles of rear shaft offered, though I have yet to determine a logical pattern behind which MJ got which. The other one was a 2-piece design, but not the usual 2-piece you're thinking of where one side slips on the other. The MJ 2-piece had a large outer tube on the transmission side and a smaller tube on the axle side. They are fused together with a thick rubber isolator designed to reduce vibrations.