I am looking at this too. I will be taking measurements when it shows up but I beleive by looking at the pictures that I can fabricate a bracket to replace the OEM bump stop and find a Firestone long travel airbag that fits that void. I will definitely send pictures if/when I undertake this. I will probably be doing it within the first six month's of ownership.Well i think most of us just want to able to tow without the dreaded sag and be safe doing so. I've done airbags on every HD truck i've owned to keep the truck level when towing. I don't get near the limit of the truck's GVWR but it certainly tows better. I for one am thinking a bag could fit inside the spring or even easier would be to swap out to a tad heavier spring rate. I'll pull one of mine this fall to measure it. I swap springs out on all my offroad vehicles and track cars. I'm talking just going up 50-75 lbs, nothing major.
IF it works the way I am planning, I beleive I will sacrifice ZERO off road ride quality but add a bunch to on road towing safety and quality. I will be able to drain the bags to 1 PSI for serious off road but put them back to 5 psi when on road without weight. Of course add enough psi when towing to accommodate the unweighted ride height...