your truck will come from the factory with a small "rake" towards the front, i.e the rear is taller so that when you are towing or loaded the truck will sit level. if your truck is a f350 it will show more "rake" than a f250 will, because the f350 has taller blocks in the rear giving it more height. suspension lift would involve some sort of mechanical lift, i.e (drop shackles, ada leaf, arc'd lift leafs, blocks"rear only") A body lift is just spacers that go between the frame and the body mounts. in order to fit 35's you would need atleast a leveling kit
thats the best i can say off the top of my head, im sure some others could chime in.