You need to:
1. Have a rear sway bar installed.
2. Run your rear tires at the Load E maximum of 80 lbs..
3. Counter-act (through use of a soft rear shock affect) the pounding in the rear from roadway cracks and pot-holes that you normally would get from 80 lbs. pressure back there - while at the same time getting a stiff rear shock affect to control sway back there - by having two of these dual-action shocks installed in the rear (to spread out your cash flow you can add them in the front later, if you want):
http://www.konirv.com/FSD.cfm4. Bias vehicle weight down low to help control sway. Travel as much as possible with as much weight down low by traveling with a full fresh water tank and a full propane tank. Having a built-in generator, which is heavy and mounted down low ... will help reduce sway too. Not loading an overcab bed up with a lot of weight will also help. Grey water and black water tanks having some liquid in them when underway will help bias the weight down low ... but of course you must be able to count on being able to empty these when stopping to camp.