At some point in the last 20 years, four-wheel-drive became common

　　on new light trucks while manual gearboxes and dash-mounted

　　ashtrays became a rarity. But in the days following World War

　　II,General Motors did not offer a factory-built four-wheel-drive

　　pickup truck, so a small vendor called NAPCO, or Northwestern Auto

　　Parts Company of Minneapolis, Minnesota, stepped up to meet the

　　demand.Armed with NAPCO's ingenious Powr-Pak 4x4 conversion kit, a

　　mechanic could transform a two-wheel-drive GM truck into a

　　four-wheel-drive in just a few hours, with no welding and minimal

　　cutting needed. The front drive axle in the package was fitted with

　　tubes modified for constant velocity joints, thus allowing the

　　wheels to steer, and the transfer case was a divorced unit, driven

　　via a shaft off the transmission, so it could be mounted without

　　altering or adapting to the stock powertrain.NAPCO conversions date

　　at least as far back as the 1947-'55 (first series) GM light

　　trucks. However, prior to 1955, only one-ton and three-quarter-ton

　　trucks could be converted, because half-ton trucks used a

　　torque-tube style driveshaft that wasn't easily adapted to a

　　transfer case. Once the torque tube was eliminated, in the

　　second-series 1955 trucks, it became possible to use NAPCO

　　conversion kits on half-tons.This GMC 3/4 ton(called the 150) is

　　believed to have the original Napco 4x4 system and is powered by

　　the inline 6, mated to a 4 speed manual transmission. The pictures

　　say it all, you'll be hard-pressed to find a nicer GMC of this era!

　　Purchased by the current owner in 2001, they spent over 16 years on

　　the restoration, going over every detail.