I put 2 extra leafs in each side so I could max the keys up front... Make sure your shackles and hangers are in good shape to handle the extra resistance... about 30 miles after I put the leafs in a shackle let go, but I knew it was on it's way out anyway. It was shaling off and gettin thin... Ford revised the shackles and they're coated now! well duh, they shoulda done that in the first place Haha