Switch to 08 newer rear springs will help with the ride and old capacity in the rear and if you swap to 05 axles it'll ride better, turn shaper, bigger brakes, easy to install, and most importantly won't break the bank. The 05 axle has 35 spline inner and outer axles, better unit bearings and hubs, stronger tube and is a true Dana 60 where yours is likely a Dana 50.