Stu ...Great write up. You and I are real close in the same set ups. Our TT axle wt is 7600 & TW is 845 & truck loaded is at 6605 of the 8200. Only been on one trip, first half not so good (had a couple issues with WD setup, made some corrections before we came home) 2nd half was amazing. 2nd trip will be next week. We went from 5500 ft to 7800 ft in about 65 miles. Non-towing #'s identical to yours but my towing #'s are .. 9.5 - 11.4. Have only 4250 miles on truck. If you'd like to discuss more, feel free to PM me.
Milo