I love it! "The fully boxed frame of the F150...blah, blah, blah..." Umm, anyone see a fully boxed frame on a Freightliner? Or a Pete? Or a Kenworth? Or how 'bout on a F250? F350? Or the bigger F-series? Anyone?
You know why? Because the frame has to flex for the torque and the load. Let's see, a 425hp Cat putting out 1800 ft/lbs of torque pulling a 45,000# load off the line and the frame didn't flex. Snap! Watch a loaded tractor trailer take off the line. Watch the left front spring up and the whole frame flex to compensate. Considering the larger F-series are "commercial" trucks, diesel optioned, the same physics apply. The frame needs to have some flex in it for the torque of the Powerchoke and the larger loads expected to carried by the larger trucks.