There are NO SPRINGS on a 97 to 03 4wd F150, sorry, if you believe there are you are wrong. Cranking the bars only causes a change in CV angle if you keep it within specs (see FSM) you will be fine. Secondly a leveling kit (spacers for you 04s) are dirt cheap and work fine, jeep owners have been using them for years in much more stressful situations then the F150 will be placed in.