2 weeks ago, I swapped my 2005 F150 5.4L Crew 5 1/2' bed (138" WB) with a 2001 6.8L F250 8' bed (172" WB) to tow my 34 foot (exterior length) Featherweight TT (5600# unloaded). Sure, it's an older truck but it only has 77K miles on it. It has a tape deck in it...my kids asked me what the tape deck slot was for in the dash). I don't regret it making the switch.
We traveled to Western MD last week to camp (about 200 miles one way). What a huge difference in stability. Highway 68 in Western MD has some significant grades (around Frostburg, MD) and plenty of crosswinds. The truck felt like an anchor compared to our F150. It's a whole new league to switch to HD and worth considering.
2011 Jayco 29L w/Outside Kitchen
Reese Straight-Line WDH
2001 F250 Lariat 6.8L Crew w/Long Bed
Honda EU2000i Generator