Back in the 1950s, Chevy and GMC didn’t offer in-house-designed 4WD pickup trucks. But Dodge had been building its trucks with 4WD since the 1940s. So the Northwest Auto Parts Company (Napco), an engineering and fabrication firm from Minnesota, began to produce conversion kits that could transform GMC and Chevy trucks (as well as Fords) into 4WD trucks.
By 1957, both manufacturers were installing Napco Powr-Pak 4WD conversions directly on the assembly line. Once the OEM manufacturers began building their own 4WD trucks in the 1960s, the Napco conversions were no longer needed. Today, Napco trucks are rare and highly desirable collectables with a strong owner’s group. This 1959 Chevy 3100 sold at a 2008 Barrett-Jackson auction for a whopping $72,600.