the GMC Division of General Motors LLC, is a division of the American automobile manufacturer General Motors (GM) that primarily focuses on trucks and utility vehicles. GMC sells pickup and commercial trucks, buses, vans, military vehicles, and sport utility vehicles marketed worldwide by General Motors
GMC trucks with gasoline V8s were equipped with Pontiac, Buick, and Oldsmobile V8s (the Canadian trucks used Chevrolet engines). GMC had its own line of inline 6 cylinder engines, known as "Jimmy's" from 1939-1959, and their own V6 from 1960-1974 (also a V8, V12). Chevrolet trucks were marketed towards private ownership, while GMC was focused towards commercial uses.
The GMC Sierra's base powertrain is a 285-hp 4.3-liter V-6 with a six-speed automatic transmission and 305 pound-feet of torque. Stepping up to the 5.3-liter V-8 boosts the stats to 355 horsepower and 383 pound-feet of torque, which improve capability