No worries. Not offended in the least. Just too tired of that particular track to take part anymore.
I did make a five mile test run w/bags fully deflated, over railroad tracks, on the interstate and surface streets, with a pretty good little range of conditions, before taking it anywhere though. Adequate usable suspension travel remaining and not even squatted as bad as you might expect. I think the WDH is doing most of the work. Losing air in the bags is a good point to consider though.
Anyway... Sorry for the sidetrack.
My experience, the 3.21/8 speed truck tended to downshift more and run up the engine RPM higher and more often, compared to my 3.92/8 speed, but still maintained speed and climbed grades just fine.
Just my opinion, having towed the same load back-to-back with trucks having 3.21's and 3.92's, I think the OP would be fine towing a few times a year at max capacity with 3.21's. The 3.92's definitely are nicer to tow with, but the 3.21's really weren't that bad.