Prior to 1957, GM sent the 2x4's to several different shops for 4-wheel drive conversion (NAPCO was one of them). After that, NAPCO was selected as the supplier and GM ran them down the line with NAPCO 4-wheel drive components.


1959 Chevy Apache Stepside 4x4
2009 Chevy Silverado 2500HD Duramax/Allison LB Crew Cab