Your weakest link in the RAWR is the tires at 3,000# each. I have a 2008 Ram 2500 CTD with LT 265 load range E tires and they are about 3,200# each. In round numbers, the dry weight of my fiver is 10,600#, ready to camp slightly less than 12,000#, and my CAT scaled rear axle weight is about 5,600#. I am about 600 lbs under RAWR.
I am starting out about 1,000 lbs less than you and I pack pretty light. I also question the advertised dry weight of the Mobile Suites at 11,500 lbs. I can't imagine you could be less than 13,000 lbs ready to camp.
About the only way I could see this working is if you want to spend the money to put both 19.5" wheels and tires as well as upgrade the rear suspension with air bags/springs. I think this would cost $3,000 to $4,500 depending on what you want to do. That's a lot of money to put into a 1999 truck. Do some research if you think you may be interested in upgrading from LT tires to 19.5" medium duty truck tires that can be rated at over 4,500 lbs per tire. This upgrade is pretty popular for folks with truck campers.
I would probably spend the upgrade money towards trading trucks for a 3500. Good luck on whatever you decide.
