Hi Huston:
Although I have a little bit of margin left before hitting my weight limit on our 3500 Dodge with our 5'er hitched up, I installed air bags on our TV soley to level the truck out while towing. My decision to install the air bags had nothing to do with weight limits. The decision was made to try to reduce the number of oncoming cars flashing their lights at me while pulling our RV during darkness.
Additionally, a close friend recently bought a new F-350 Ford having the same problem when his pickup camper was loaded. His weight limits were fine, but his headlights were blinding oncoming traffic. This was easily cured with his installing a set of air bags. I would suggest you consider the position at which your truck sets at with the pin weight laden on the truck hitch. Happy travels, gebills.