What did to get 35's under her is, crank the T-bars to level it out...free.
Then when with a 2" body lift...$200, did the install myself.
My truck was a 2000 4x4 4.6L, I did not regear and the truck still had enough power to pull a work trailer full of tools, but I would suggest a programmer.
2012 XLT F150 (Sterling Grey)
Tonneau Cover, 15% Tint, 6" Rough Country Lift, 18" Helo 6 Wheels(chrome), 35" Toyo Open Country A/T's, SuperChip, Rear Wheel well Liners, Hood Shield,
Window Visors, Fender Flares