1978-91 Chevy/GMC Truck Chrome Steel Front Differential Cover - 10 Bolt w/ 8.5" Ring Gear Chevy/GMC chrome steel front differential cover with 10 bolt pattern. Fits 10 bolt Chevy/GMC truck front ends with 8.5" ring gear. Includes drain plug. Fits 1978-88 Chevy/GMC 1/2 Ton & 3/4 Ton - Front. Fits 1977-91 Chevy Suburban 4WD - Front.