2. It's debatable whether to weld everything up in the air or on the ground. When you weld something like a brace (or in this case, stiffener) the metal will bend towards the weld. You can use this to your advantage. If a Cherokee is already a little bent and the doors are hard to open, then get the weight off the axles and lift it more in the center before welding the stiffeners. You can often pull the body back into better shape and the doors will open more easily again.