In the mid-1950s, General Motors light duty trucks weren’t delivered from the factory with four-wheel drive. The only way to get a 4×4 Chevy pickup was to have a mechanic install the ‘Powr Pak’ conversion produced for GM by the Northwestern Auto Parts Company or NAPCO, which would turn a 2 wheel drive truck into a four-wheel drive one in just a few hours. NAPCO converted Chevys are hard to come by today, as the kit was only used on GM trucks from 1955 to 1957, but a gleaming example recently popped up for sale on Hemmings for $55,000.
This 1956 Chevrolet 3100 is a half-ton shortbed example with the big back window and the rare NAPCO-developed four-wheel drive system. The interior, exterior, underbody, engine bay and the 3.9-liter inline six-cylinder engine itself are in concours condition thanks to a full frame-off restoration. The entire drivetrain is all original and was also completely rebuilt when the truck was restored.
It’s impossible to tell a NAPCO-equipped truck from the exterior, however there should be NAPCO cast into the front axle to identify it. Hemmings didn’t provide any pictures of the stamp itself, but you can be sure this is a real NAPCO 3100. Check out the ad here for more photos and information.