And ??
You sure a 6" lift will clear the rear fiberglass or let you steer? Heres a 4 " lift, stock rubber, 235/85R16s, 31" tall....
but you know this. Without moving the front axle ahead, you will not clear the back of the front wheel opening. And just measure how long the rear wheel well opening is. Plus add in a regear.
This is a pipe dream. Not happening with the vehicle in the post. There is physically not enough room. But you have a great vehicle, even with stock rubber.
But, to the point. 6 winter tires will out perform 4 of any LT AT/MT whatever. Ford built a well balanced vehicle. Converting to Super Singles and lifting it to fit them will cost more than buying a new vehicle which meets your spec. And likely still not perform better than it does now. Listen to the guy running 6, 235/85R16s.