Separate the half of the suspension that locates the axle under the truck from the half that holds the weight of the truck up. That way you can use a spring that is just stiff enough to support the truck, and use solid steel tubes to locate the axle. The Skyjacker Z-link kit was designed to do just that and replaces the leaf springs on the front of Ford Super Duty trucks to give you a better ride while eliminating any axlewrap.