Inside your drivers door, is a yellow sticker. It will say Passenger capacity, or carry capacity, something that gives us a hint what your 'payload' is? This is for your exact truck, not found anywhere but your drivers door (well maybe in some build sheet). What year Expedition is it? What motor do you have? I / we ask this, because often stuff hyped up in brochures or at Dealers, are not exactly whet your specific Expedition might have been ordered with. Lastly, I drive a 2005 YukonXL, 4wd, 5.3 V8, tow capacity 8100 lbs, and I would never attempt anything near your size, ever. In my opinion, you are 100% in 3/4 ton truck area. Give us the above numbers and we all will help you sort through this. I have a personal interest, I'm considering replacing my Yukon, and the Expedition seems like a possible option, I'd like to see your yellow sticker payload numbers.