 For 1977 only, the full-size GM product line adopted a smaller exterior footprint than the A-platform intermediates; careful engineering led to negligible reductions of interior space over preceding full-size vehicles.In both the interest of fuel economy and weight reduction, the B/C-platform ended the use of "big-block" V8 engines outside of the Cadillac division; after 1980, a 350 cubic-inch V8 was the largest engine fitted in a B-body chassis.In 1985, General Motors underwent a further downsizing of many of its nameplates using the B-platform chassis.