Good original 1994 Chevrolet and GMC Truck Dealer Service Manual Set. These Manuals cover the G-Van Models.  It includes the Service Manual as well as the Driveability, Emissions and Electrical Diagnosis Manual. These have Information, Illustrations, Diagrams, Specifications, Procedures and Trouble Shooting for these vehicles. These are what the Dealership used to repair your Truck.  Very informative and useful tool that is hard to find since they were not available to the public.