You missed one important calculation I think
All the math on weight is great but you're missing one important one - perhaps the most important one.
GCWR. You listed it as 11,000 lbs.
Your SUV weighs 5000 or so lbs (6400 gvwr-1342=5058). Approximately. Options can change that by 400 lbs as sunroofs, running boards, heated seats, third row seats, bigger tires/wheels can add up.
The hitch assy is gonna weight 70 some pounds. The trailer, empty, 4800 lbs or so. Your family weighs 570. Propane, batts on the trailer and gas in the truck are additional to all these other weights - 120lb for trailer and at least 200 on teh truck.
5000 + 70 + 4800 + 570 + 120 + 200 adds up to 10,760 lbs.
The total GCWR can only be 11,000 - that leaves 240 lbs for food, clothing, pots and pans, bedding, bath supplies, leveling blocks, fire wood, camping chairs...not nearly enough extra room.
From what I"m finding out (doing this same math and research) the GCWR is based on what the transmission can handle, and perhaps the engine's power/torque output. Final gearing is the biggest piece of the puzzle as it controls the load on the transmission. It's also what ford says will be damaged if one exceeds GCWR.
There are things you can do to improve this situation of course -new taller gearing in the truck is one ($300-600 or so, more for 4x4 as you need 2 ring and pinions), shorter tires/wheels (used it's cheap, new it's not), bigger trans cooler (cheap) or a HD towing rebuild on the transmission ($3-4,000).
If you only tow once a year for 100 miles in Kansas or something it may not be big deal, but load up for 2 weeks on the road and head into the mountains and you stand a fair chance of having an unexpected delay and cost for repairs.
Jill & Chris, Wills (14) Evie (11) & Toby our collie (5)
2011 Grey Wolf 28BH
2013 Chevy K1500 Crew w/ Reese StraitLine Dual Cam
Nights camped 2011: 11 2012: 18 2013: 12 2014: 12 2015: 13 2016: 3