Mock, CX scaled a couple of hundred pounds below GVW (9200#) when fully stocked with food & clothing for a multi-day trip (about 10 gallons of water, empty black and gray), including me and the cat. That includes the big heavy 8.1 & Allison, the Onan, and the roof A/C. Plus I tend to carry a lot of tools, some books, and other stuff. That's on a 2500 chassis, so there should be lots of unused weight capacity on a 3500. If you're traveling with a pet, I really suggest the Onan.
Jim, "Keep clam and proofread."