What kind of terrain do you anticipate towing over? How many trips? Can you keep your trailer as lightly laden as possible (near empty tanks and propane)?
While in general the 3.92 gears would have been a much better choice, people tow at or above their gcvwr often. (Reality)
Tuners aren't really your friend when towing, so slow down,. Don't think that your air bags do anything to increase payload (they just level out) and strongly consider an appropriately fitted WD hitch system. This will help not only your tongue weight, but also handling and steering/braking. I cannot overemphasize the WD hitch issue enough for you.
Otherwise, anticipate slower starts, and you'll want to monitor transmission temps (be sure to lock out 8th) as well as engine temps. Consider changing tranny fluid more often, as well as coolant. Go to a CAT scale and weigh each axle separately, and then make WD bar and load adjustments needed.
Lastly, go to an RV forum to get your dose of "You'll kill yourself and everyone else on the road" and "To tow that much weight you need a 3500 drw..."