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In the 1950s the Northwestern Auto Parts Company became a publicly traded stock company and changed its name to NAPCO Industries, reflecting it's change of focus from wholesale supplier to manufacturer.  In addition to manufacturing, the company began a program in earnest of tracking the availability of blue prints and vendors and prices of all the equipment requested by its world wide customers.  That computerized system has evolved to become today's model for the industry.  The company also adopted the quality standards required of manufacturers serving the US Defense Department.

The date that NAPCO started to produce 4x4 conversion units is a little foggy.  I have heard stories of GM trucks being converted as early as late 1949, but the earliest documentable truck that I have ever heard of is a 1951 Chevy 3/4 ton owned by Butch Gehrig of Odell, OR.  Until October 28th of 1954, when Chevrolet introduced the '55 1st Series, all the conversions were done on 3/4 ton and larger trucks.  The '54 and earlier Advance Design 1/2 ton models were not suitable for a NAPCO conversion due to the enclosed drive shaft design.  GMC and Chevrolet conversions were by far the most popular, though conversions were available for Ford, Studebaker and other manufacturers.

Though the date of the first NAPCO 4x4 conversion is unknown, we do know that in July and August of 1954, NAPCO was very busy pushing its proven 4x4 conversion on truck upfitters and GMC dealers across the country.  Upfitters were companies that installed upgrades and accessories like winches, auxiliary transmissions, tandem drive axles, dump bodies and hydrovac systems on stock factory trucks.  The NAPCO slogan proudly stated:  "Now you can  have a standard Chevrolet four wheel drive pickup featuring the traction power of a tank, or, at the flip of a finger, a smoother riding, high speed, over the road truck.  Aptly named the Mountain Goat, this full sized pickup will literally leap up mountains, as well as carry you through deep mud, sand, or snow.

Apparently NAPCO reached an agreement with both GMC and Chevrolet to supply them with the Powr-Pak conversion kits, and GMC began to produce 4x4 trucks on the factory assembly line (using NAPCO components) starting in 1956, with Chevrolet following suite in 1957.   By the end of 1957 both GMC and Chevrolet trucks could be ordered from the factory with the NAPCO Powr-Pak conversion.  The two offered identical systems other than the availability of a V-8 and an automatic transmission on the GMC trucks.  The Chevy could only be ordered with the 235ci six cylinder and a four speed manual (although there was nothing stopping an owner from ordering whatever he or she wanted in a 2 wheel drive truck and then having a NAPCO Powr-Pak "upfitted" by the dealer). 

Some features of this early "shift-on-the-fly" 4x4 were the unchanged turning radius, a full engine torque P.T.O. option, a rubber mounted transfer case for long, silent operation, greater ease of steering, and a guarantee of no damage to the Chevrolet or GMC frame during the three hour installation.  Yes, only four holes to drill and no torch cutting!  In a matter of hours, you could go from a two wheel drive to four wheel drive and the NAPCO Powr-Pak could be transferred from one GM truck to another. 

If a dealer had a truck in stock that he wanted to convert to four wheel drive by using the NAPCO Powr-Pak, he could order the Powr-Pak four wheel drive package.  Soon, a wooden crate, 80 inches long, 30 inches wide and 26 inches deep would show up on his loading dock weighing in at 1,410 lbs. with all the necessary parts enclosed.  It also gave truck owners and dealers the distinct advantage of quickly removing the conversion package and transferring it to another truck, without damaging the originality or resale value of either vehicle (except for the four bolt holes in the frame.) 

The NAPCO two speed 4x4 conversions were comprised of 85% GM parts.  That meant for the most part they were serviceable by a local dealer.  Complete front axle differentials, brake drums, wheels, drivelines, backing plates, springs, shock absorbers, and universal joints were all Chevrolet replacement parts, which are still available from a variety of sources today.

A 1/2-ton, two wheel drive pickup listed for $1,548.96 in late 1954.  The retail price of the Powr-Pak was $995, which included a dealer freight cost of $800 from Minneapolis, Minnesota.  Installation by an upfitter or equipment company included the cost of the Power-Pak, and listed at $1,248.  This brought the complete list price of the finished truck to $2,796.96.  These conversions were done on the 1/2 ton, 3/4 ton, one ton, and the two ton trucks, as well as the Suburbans and panels.  Again, the conversion was not available for 1954 and earlier 1/2 tons because of their enclosed driveshaft design.

The first "all GM" factory 4x4's were introduced in 1960 when both Chevy and GMC went to a totally new chassis.  NAPCO and its Powr-Pak conversion were left out of the equation due to the introduction of GM's completely redesigned truck line featuring independent front suspension on the two wheel drive trucks and a 4-wheel drive specific chassis on the 4-wheel drive trucks.  This was the beginning of the end for the 4x4 conversion element of NAPCO.  Though they did produce conversion kits for a few more years, their main business shifted to the heavier trucks, 1-1/2 ton and larger.  A few later model specially built custom vehicles featuring the NAPCO components are still out there, such as Mr. Packy Pickrell's 1970 Chevy 1 ton NAPCO.

After the huge loss of the contracts with GMC and Chevrolet to supply conversion packages, NAPCO sold the rights to the Powr-Pak package to the DANA Corporation.  I haven't found the date yet when that actually occurred, but we can safely assume it was after 1960.  All documentation, archives, information and parts were transferred to DANA at that time.  During this evolution, the association of the NAPCO name with 4x4's ceased to exist.  The NAPCO 4x4 had vanished, just as it's associated history, archives and NOS parts supplies were absorbed into DANA.

During the years following the demise of the NAPCO 4x4, NAPCO has broadened its product line to include communications equipment, aircraft spare parts, logistics services and many other products and services.  Due to corporate changes not related to its defense business, the company's name changed from NAPCO Industries to NAPCO International in the 1980s.  Though they haven't produced the 4x4 conversion in any quantity for nearly 40 years, the company has continuously improved the efficiency, quality and breadth of its product line through deployment of new technologies, training, and hard work.  They have expanded and live on today. 

When asking questions or searching for any information concerning our NAPCO 4x4's, it becomes readily apparent that "all roads lead to the DANA Corporation."  But why DANA, as the SPICER name is most commonly used in conjunction with NAPCO?  We've heard that "DANA bought out SPICER." and that SPICER bought out NAPCO.  Well, that is just NOT the case.  We've got to understand just what's what in this Quest for NAPCO, and the story has all the twists and turns of a good Agatha Christy novel. 

Go to Chapter 2

In "The Quest For NAPCO" Kevin Pennell explained to you the why's and the wherefore's of this endeavor.  The "awe" that he still feel every day while looking at his NAPCO 4x4 and his frustration with the search for parts and information have made the development of this "History" section a personal mission of discovery for him.  "Inquiring minds want to know!"  What filing cabinet in the sky did NAPCO vanish into when they were bought out?  His purpose is to get some hard, real information out to the NAPCO owners who need it the most.  He has had some luck, and present that information for you here.  He personally tried to confirm all of the information with at least two separate sources and more when possible!  Everybody hates having something presented as "gospel", only to find out later that it isn't quite right.  Information about the NAPCO Powr-Pak 4x4 Conversion is locked up in the minds of folks scattered all over the country, and is scarce as hen's teeth.  If you know anything about this early company, or about these NAPCO trucks please contact us.

Special Thanks
Sources for the following information include an article written by

Mr. Seth Doulton, former owner of Golden State Pickup Parts
Mr. Tom Brownell's How to Restore Your Chevrolet Pickup
Mr. Joe Fox and Mr. Kevin Lake of  The NAPCO Owners
Mr. Woody Morcott, Mr. Pat Long and the DANA Corporation for great information and the use of copyright material from The Illustrated History of DANA Corporation, Copyright 1998
NAPCO International, Inc
., whose ancestors are responsible for the awesome 4x4's we've become so attached to. 


"NAPCO" stands for the "Northwestern Auto Parts Company" of Minneapolis, MN., though their production facility was actually located in Plymouth, MN.  I've been told that the abandoned old plant still stands with a weathered sign posted, sadly advertising times gone by.  NAPCO had been in business since 1918, and during W.W.II, they focused all their attention on projects commissioned by prime contractors to the United States government. Mainly, this meant the production of specialized automotive parts and assemblies that could be tested on the largest proving ground in the world.  After the war, the military's priorities changed, and NAPCO re-directed its vast engineering and manufacturing experience to the production of goods for private industry, which included the production of the famous NAPCO Powr-Pak 4x4 Conversion.  I've heard countless times that NAPCO was bought out or had gone out of business in the early 1960's.  This is just not true.
Northwestern Auto Parts Company 1918