I have a 1998 Ram 1500 Quad cab 4x4 5.9L 150,000 miles that I need to replace the upper ball joints and I figured I would replace all the steering components. My kids and Mrs. have driven this truck and I have noticed the tires wearing inside of left tire and outside of right tire and steering wheel no longer straight. I have been looking for a complete kit but most of the kits say light duty 4x4 front suspension. How do I determine light duty and heavy duty?