By 1980, both Ford and International Harvester had released redesigned medium-duty trucks, leaving General Motors with a 7-year old product in the marketplace and its school bus chassis dating from 1967.
Featuring a tilt-forward fiberglass hood as standard equipment, the B-series was powered by three V8 engines, the 366 and 427 gasoline engines and the Detroit Diesel "Fuel Pincher" diesel.