Towing Air Bag Kit Over Load Level Rear Suspension. 1973-78 GM 1/2 ton Truck. Requires minimum 7 between rear tire & frame. Kit Includes: Two – Standard 2500lb Air Springs Mounting Brackets With Hardware 1/4 D. Approved Air Line With Fittings And Schrader Valve. Provides Up To 5000lbs Of Leveling Capacity Easily Add Or Remove Air Same As You Would A Tire. Never exceed more than truck manufacturers maximum load recommendations. Cutting, drilling & welding are required for install professional installation is recommended.