1983 GMC Trucks School Bus Chassis Sales Brochure. Consider this. Electrical system. Easy starting. Corrosion resistance. Power. Transmission - manual or automatic. Power or manual steering. Front axles. Rear axles. Springs. Brakes. Tires. Parts and Service. Keep operating cost records. GMC B6P042 cowl model chassis highlighted. Specifications on back. Specifications for P-3500, Vandura, and B6P042. Condition: Rusty staples. Some soiling. See pics.