I've got a 2005 Expedition Limited with the HD towing package with 85,000 miles. So it's got the 3 valve 5.4, air bag suspension, and rated to tow 8600 pounds. I'm looking at a travel trailer that has a dry weight of 6350lbs, GVWR or 7700, and a hitch weight of 800lbs. I've towed a lot over the years but honestly never anything pushing the limit as this seems it would be. My biggest concern is the payload of the Expedition of only 1483lbs, with 5 people and the hitch weight we'll be pushing it. I will have a WD hitch, anything more I can do to make sure hitch weight isn't too much? Does it seem I'd be safely within the limits and not fry a tranny?