The horizontal door on the rear storage compartment indicates it's an 11.5' model. The 9' model would have a vertical door.
I found some info on a 1996 model:
1996 Fleetwood Caribou 11’6” cab over camper
2470 dry weight
Fully self contained with a dry bath (very rare for campers)
Full queen size home type mattress over cab
Dometic Fridge Freezer 2 way combo
A/C (will literally run you out of the camper VERY big unit)
Fan force furnace with t-stat
40 gallons fresh water
27 gallon gray water tank
27 black water tank
Outside shower
Luckily the older campers are much lighter than current models. You should be able to put a reasonable amount of stuff in the camper and still be ok on your Dodge 2500. It may need airbags and better tires just to make you feel comfortable, but it should be within your axle ratings.