This is a second-series truck with the new-for-1955 styling — and a very rare NAPCO 4x4 conversion.

1955 was the first year General Motors offered the new half-ton pickup with 4x4. NAPCO 2-speed 4x4 conversions were composed of 85% GM parts. 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 ride over the road.”

This truck has been treated to a very high-quality frame-off rebuild. It is powered by the famous 235-ci 6-cylinder engine and 4-speed transmission. The extremely straight body is finished in Chevrolet Neptune Green. The interior is refinished to original, with woven plastic beige seat covering and matching dash color. The box has been redone with wood boards painted low-gloss black as original. All chrome, grille, bumpers and emblems are new or replated.

SCM Analysis


Vehicle:1955 Chevrolet 3100 NAPCO 4x4 pickup
Years Produced:1954–59
Number Produced:329,791 (total second-series trucks, NAPCO conversions unknown)
SCM Valuation:Median to date, $37,300; high sale, $66,960
Tune Up Cost:$150
Distributor Caps:$12
Chassis Number Location:Tag spot-welded to the upper forward driver’s door frame, stamped aft of the steering box on the left chassis rail (exact location varies by assembly plant)
Engine Number Location:Side of block, behind distributor
Club Info:The NAPCO Owners Group, American Truck Historical Society
Alternatives:1959–60 Ford 4x4 pickup, 1953–60 International 4x4 pickup, 1946–68 Dodge Power Wagon pickup
Investment Grade:B

This truck, Lot 1015, sold for $63,800, including buyer’s premium, at Barrett-Jackson’s auction in Scottsdale, AZ, on January 26–31, 2016.

From humble origins to GM supplier

NAPCO stands for Northwestern Auto Parts Company of Minneapolis, MN. It began in 1918 when Romanian immigrant Edward Rappaport started buying wrecked cars and parting them out in his backyard for resale. By 1924, it had become Northwestern Auto Parts Company, and it experienced explosive growth as a parts wholesaler and manufacturer, especially in truck components, up through World War II.

During the war, NAPCO was a component supplier for a number of military vehicles, including the M8 Greyhound armored car built nearby at Ford’s Twin Cities Assembly Plant in St. Paul. By the end of the war, the company had a very good handle on what worked and didn’t work for off-road equipment, and under the NAPCO trade name, it began marketing a “Powr-Pak” four-wheel-drive conversion kit for light-duty pickups in the early 1950s.

Although they were available for most truck makes, the vast majority of Powr-Paks were made to fit Chevrolet and GMC. Ford primarily contracted with Marmon-Herrington for four-wheel-drive conversions, dating back to 1936. International began building their own four-wheel-drive trucks in-house in 1953, with Coleman seeing some contract work with larger trucks. Dodge offered the Power Wagon in 1946 almost as quickly as possible after the war ended. All this meant that GM was the lone major automaker without a four-wheel-drive model, so it took the lion’s share of NAPCO Powr-Paks for its trucks. Studebaker was the next largest in Powr-Pak sales, but sales were meager.

Factory- or dealer-installed

By 1954, the Powr-Pak was a GM-authorized accessory for upfitters of vocational equipment. The kit could be installed either by a local dealer or distributor. However, it was only available for three-quarter-ton and larger Chevys due to the torque tube arrangement on the half-tons. All GMCs had a conventional driveshaft, so its half-tons could be NAPCO-equipped.

All 1955-production Advance Design Chevys went to an open driveshaft over the previous torque tube in preparation for the new mid-year Task Force series trucks. That opened up an even bigger door for GM NAPCO conversions.

By 1956, the NAPCO conversion could be factory-installed on GMCs, and Chevrolet followed suit by offering it from the factory in 1957 — although the 1,410-pound kit could also still be dealer-ordered and installed as well.

Assembly plant installations on Chevrolets were only on 6-cylinder/4-speed-equipped trucks, while GMCs could be done with the V8 and even the optional HydraMatic transmission. However, since it was still a dealer-installed option, in theory any Chevy pickup could be fitted with one — including Cameos — if a customer so desired. And on that note, they were also fitted to Suburbans and panel delivery trucks.

End of the light-duty line

For 1960, GM changed over to an independent front suspension on its half-ton two-wheel-drive pickups, and they developed their own light-duty four-wheel-drive system. With the combination of a more unified in-house system with a dedicated 4×4 chassis and the complexities of converting from IFS 2×4 to solid-axle 4×4, NAPCO conversions for C-series were only available on medium- and heavy-duty trucks — although NAPCO did market the earlier Powr-Pak kits for a couple more years for earlier trucks.

Shortly after 1962, NAPCO sold the rights, tooling, and intellectual property of the Powr-Pak division to driveline systems manufacturer Dana Corp.

Cresting the market

NAPCOs have always climbed to the top of the collector market in terms of values, and they continue to do so.

Utilizing well-engineered components, such as the gear-driven Spicer 23 transfer case, trucks with a NAPCO conversion always had a cachet over a garden-variety two-wheel drive — even in rougher-than-a-cob condition. As such, these trucks tended to be saved in greater numbers, even just as a backup tool or as the sum of the NAPCO parts, removed from a dead rusted-out example. So these trucks tend not to be as rare as some would suggest.

The demand for a NAPCO Chevy has always meant that the prices have stayed high on them, especially over the past decade, where the market has seen steady increases in values on all vintage pickups.

As the kit was billed as being easily transferable from one truck to another within six hours (three hours to remove, three hours to install — to include drilling four holes in the frame — as estimated in the instructions), it’s difficult to claim that a given Task Force-era GM today was ordered from new as a NAPCO without some sort of documentation. However, pricing history shows that it’s more or less a moot point, with only a slight premium of about 10% for a verifiable factory or original-selling-dealer installation.

No chrome queen

This example is also like a lot of NAPCO conversions that have surfaced on the market lately in that it’s a high-quality restoration and isn’t festooned with a lot of aftermarket trinkets. This one now has chrome bumpers and grille over the entry-level painted parts, but that’s it. Those who restore these trucks tend to “get it” and do them up as authentic to when they were new. Even the bed wood was correctly painted on this truck, unlike so many pickups that have nicer wood floors than multi-million-dollar mansions.

This looks like it was just delivered to a GM dealer, and is ready to have a utility’s name or a state’s Game and Fish Department emblem stenciled on the doors. As such, while the price seems a bit steep, it’s not all that outrageous with regard to the market. You may find a similar truck for less, but not by a whole lot. And it won’t likely be as authentically done as this market-correct rig. Call this one well bought and sold.

(Introductory description courtesy of Barrett-Jackson.

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