all cherokee stock specs... at least anything that anyone has thought pertinent...
http://www.jeepforum.com/forum/showthread.php?t=26256
the info you are looking for:
Rear Axles:
Dana 35 non c-clip - 27 spline, 1.18" diameter shafts, 7.58" ring gear, 2.62" axle tube - used
84-89
Dana 35 c-clip - 27 spline, 1.18" diameter shafts, 7.58" ring gear, 2.62" axle tube - used
90-01
Chrysler 8.25 - 27 spline, 1.17" diameter shafts, 8.25" ring gear, 3" axle tube - used
91-96
Chrysler 8.25 - 29 spline, 1.21" diameter shafts, 8.25" ring gear, 3" axle tube - used
97-01
Dana 44 non c-clip - 30 spline, 1.31" diameter shafts, 8.5" ring gear, 2.75" axle tube - used
87-89 on some(not all) XJs equipped with towing package.
Gearing:
3.07 - used with 4.0L engine / manual transmission
3.31 - only available on older (pre87?) 2 door XJs with "Fuel Economy" package
3.55 - used with 4.0L engine / automatic transmission
3.73 - found in some XJs with the towing package
4.10 - used with 2.5L engine usually, and older XJs with the "Off-Highway Vehicle" package.
4.56 - rare but can be found on some older (~ 89 ~) models with 2.5L engine and auto transmission