Here's a beautifully illustrated two-page magazine advertisement for the GMC V-6's debut. The General Commands You to Go to Work 1959 GMC Crackerbox hauls max payload in every state ...

GMC offered single- or tandem-axle configurations for the trucks. You could spec a 702 cubic-inch GMC V112 gasoline engine, or your choice of Detroit Diesel 6V71 and 8V71 engines.