Original sales brochure the 1988 GMC Truck Trailering sales brochure covers everything a GMC owner needs to know when towing behind your vehicle. This brochure is more technical and provides charts that provide information such as trailer classification, maximum trailer weight, maximum tongue load, engine, transmission, axle ratio, brakes, battery, cooler, cooling, generator, harness, shock absorbers and more for specific vehicles. Notes whether required or recommeded. Good condition, clean. 89-88 USA