First off... I don't think any mod should warn posters (who are remaining civil) that they shouldn't really speak on something that is outright dangerous for the OP. This is the exact reason that forums exist. For members to share their experience and knowledge. It shouldn't be limited to only sharing information that benefits a poster even if that information is false.
We all know that too many believe that these trucks will pull the space shuttle because uncle Bobby's nephew Tom's son Billy Joe has a 2500 that he hauls yachts with. It's our responsibility as a forum to help guide members down the right path and sometimes that requires telling them what they may not want to hear. It would be a disservice to forum members and our Ram brethren if the common answer is "Yep... that'll do just fine" when the reality is that it won't. The fun part about today's society is how quickly everyone has to clam up so as not to offend others with the truth. We need more truth, and less feelings. I want the OP to enjoy his truck... and I want the OP to have many years of fun camping and exploring the outdoors. It's my family's favorite thing. But that also means that I may have to share the road with him and I don't want to put my family at risk over a "good deal". How good is it if something goes wrong?
Anyhow... off my soapbox.
While I think this is an extremely overloaded combo and while I would absolutely never under any circumstances recommend trying to "make" the truck do something it was never intended to do.... here we are and I'd rather try to help keep the guy right side up. There may not be room in the garage to move the cargo back to alleviate pin weight.
First things first... airbags do nothing to help payload and you've got probably close to 4k on the truck with the garage empty, and depending on what you're hauling in the garage that might come down to ~3,300-3,400 lbs. All of that weight is still sitting on the axle, so keep that in mind. There are no HD coil springs to correct this much issue. If you "really" insist on keeping this combo (which I adamantly advise against), I would suggest swapping over to a 3500SRW leaf spring suspension.
Both the standard output 6.7 with the 68RFE 2500/3500 SRW come with the 11.5" AAM axle. You get a 12" axle in the HO/Aisin combo. Upgrade to the Hotchkiss (factory) leaf spring assembly, ensure that your tires are capable of handling the weight, and then consider airbags if necessary (they likely will be). I would even consider adding the DRW helper spring and spring perches. This is 100% dually territory all day long but you can "make" the truck do it a little safer than the band aids you're trying to put on it now. All assuming of course, that you stay under the RAWR.
I would still say that you need a dually, but this alternative is much better and safer than what you're currently attempting. More costly, yes... but if you're going to do it at least do it right.
