The rear end of my WJ sags really bad when towing my boat (tongue weight is only 350lbs). I know I need new shocks. Now will just shocks prevent sagging or do i need new springs? I really dont want to lift it with HD springs if I can avoid it since I have a set of 20inch SRT reps waiting for tires. Anythoughts on how to prevent this. Its weird. Same boat on my moms WJ and its perfectly level, and I have seen many WJs towing much heavier loads with more tongue weight and no weight distributing hitch. Whats failed on mine?