Of the
Big Three USA automakers, only Dodge responded quickly to the demand, introducing the first civilian production 4x4 truck with their military-type WW2 proven medium-duty
Power Wagon in 1946. After the war, NAPCO shifted again to produce peacetime machinery. As early as 1947, NAPCO began manufacturing an
aftermarket 4x4 Conversion Kit they named
Powr-Pak, that could be bolted onto any truck chassis equipped with
Hotchkiss drive. Powr-pak versions were built that fit
Dodge,
Ford,
General Motors (
Chevrolet and
GMC), and
Studebaker trucks, but the bulk of the Powr-Paks sold ended up on GM's 3/4 and 1-ton
pickups (no 1/2-tons, since they used an incompatible
Torque tube until 1955). The
transfer case was a
Spicer unit with optional Dual-Range Hi-Lo, but the rest of the Powr-pak kit (85%) consisted of readily available Chevrolet parts (wheels,
drum brake assembly, front
axle,
leaf springs,
shock absorbers,
driveshafts and
universal joints). One notable feature was the "
shift on the fly" rubber mounted transfer case that provided a smoother ride. Powr-pak offered options for Hi-Lo dual-range and
Power take-off (PTO). NAPCO also offered an assortment of winches, auxiliary transmissions, and other truck parts. The Powr-Pak kit was shipped in a crate measuring 80"x30"x26" and weighing 1,410 pounds. It could be easily installed by an owner or a dealer, requiring as few as 4 holes to be drilled in the chassis. In as little as 3 hours, a full-size truck could be converted into a 4x4 "Mountain Goat" that would climb steep inclines with ease. Just as easily, the kit could be removed and re-used on another truck, and this was used as a selling point. The retail price of NAPCO Powr-Pak kit in 1955 was $995. Many companies would install them, the price rising from $1250 to $1550 with labor, bringing the total price for a new GM pickup from $1,548.96 for 2WD to as low as $2,796.96 for 4WD. In the 1950s the NAPCO became a publicly traded stock company and changed its name to
NAPCO Industries, reflecting its change of focus from wholesale supplier to manufacturer. In addition to manufacturing, the company began tracking availability of blue prints, vendors, and prices of all the equipment requested by its worldwide customers. ==1956-1959 GM Factory Installed Option==