The shortbed Comanche is 113" and the longbed is 119" (approx)
Both style XJs are 102" (approx)
The MJs and similar year XJs are 'identical' up to a point approx under the seat/rear edge of the front doorjamb: 4-door XJ front doors and MJ doors are the same, as is the crossmember. The XJ continues it's uniframe in a straight line back but the MJ begins to flare outward... The XJ leaf springs bolt outboard of the framerail - The MJ leafs bolt underneath.