And as referenced in your original post, I told you then (2 or 3 pages in) that you weren't buying enough truck. I said an HDPP truck would be needed for that rig, and quite a few blew me off.
Maury82 and I know WTF we are talking about when the HDPP comes into play. I've had other F150s and they are soft mush not suitable for towing heavy (9000-10,000 lbs). I wouldn't tow over 5000 with any of the 5.5 foot F150s. Too short, too light, not designed for mass.
My 18 HDPP 6.5 bed kicks @$$ towing 9,000 lbs and 35 feet, and I have dealt with 40+ gusts from the side without even a wiggle. Good hitch, setup right, right truck. Amazing what that will do.
Mike