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1955 GMC NAPCO - Open Range

Bob Ryder
May 1, 2006
Photographers: Dan Ward
Photo 2/2   |   1955 Gmc Napco front Side View
It's cool to hear of a marriage that has been fused with love, devotion, and the passion for custom trucks. John and Chris Oliver from Leetonia, Ohio, have shared a common bond of custom cars and trucks during their 16 years of marriage. John is a successful contractor who has found time over the years to build a multitude of gorgeous street rods, muscle cars, and recently, trucks.
You know a couple's love for one another is sincere when a husband goes as far as building this rare and cherry classic '55 GMC NAPCO 4x4 pickup for his wife. Most will express their love with a bouquet of flowers or an exotic vacation getaway. While attending a custom car/truck show in Florida, Chris discovered this rare ride in a local (Florida) truck trader publication. There was one hitch: the truck was located in Boise, Idaho. Following the show in Florida, John and Chris drove all the way from the show to Boise, Idaho, (2,406.4 miles) with trailer in-tow. After arriving and examining the 4x4 NAPCO, a deal was made and John stuffed the pink slip into his wallet. The GMC was loaded onto the trailer and the journey home to Leetonia, Ohio, (2,091.2 miles) was begun. A total of 4,497.6 miles was made to retrieve their unique treasure.
After the GMC was rolled off the trailer, it was disassembled all the way down to the frame; it too was stripped down to bare metal. The frame was then powdercoated satin black by the team at A Plus Coatings in Columbiana, Ohio. The NAPCO 4x4 "Shift On The Fly" Powr-Pak suspension was refurbished stock with both front and rear axle differentials, drivelines, universal joints, drum brakes, backing plates, and shift linkage. Leaf springs (both front and rear) are dampened by Rancho shock absorbers. A set of 16x12.50-inch Eagle polished aluminum wheels are wrapped with 33/12.50-16 General Grabber ST rubber.
A '78 Chevrolet 400ci engine was disassembled; the block was magnafluxed and machined by Tub Tushine in Leetonia, Ohio. Tub installed a set of J&E flat-top pistons and Crower I-beam connecting rods and Crower crankshaft. The Vortec cylinder heads are complete with stainless valves, roller rockers, and heavy duty springs. A pair of Sanderson ceramic-coated headers were bolted up to the Vortec cylinder heads; 2-1/2-inch diameter exhausts flow into a pair of Flowmaster mufflers. Following the engine dyno break-in period, a couple of power pulls were made, producing 426 horsepower and 560 lb-ft of torque! After the crew at Rossler's transmission modified the valve body, dropped in some beefed up clutches and other performance internal components, the 700-R4 transmission was bolted up behind the healthy 400ci block. The rearend was refurbished with new axle and pinion bearings, then stuffed with a set of Richmond 3.73 gears.
The all-steel GMC NAPCO cab, fenders, hood, and bed were fairly straight. It was delivered to Joe, an ol' schoolmate of John's, who is a full-time painter for a Dodge dealership in Leetonia, Ohio. He occasionally takes on custom body and paint side jobs. Joe straightened, then filled and sanded until every wrinkle and imperfection was removed. It was then colored with PPG Viper Red and color sanded between coats before the final multiple clear coats were applied. It was then cut, buffed, and polished until the deep mirror finish appeared. A beautifully crafted Pros-Pick cedar wood bed floor is separated with stainless steel stringers.
An Alpine CD head unit and 600-watt amp produce ample vibes through the two 6-1/2-inch diameter Alpine speakers. Ron Garrod Upholstery is responsible for the flawless retro red/white leather tuck 'n' roll bench seat and matching door and kick panels. The simple interior is timeless. An ididit tilt steering column is capped with a white leather-wrapped LeCarra steering wheel. Whiteface Classic Instruments fill the six-gauge cluster on the dash.
It seems Chris and John's '55 GMC NAPCO is an award magnet wherever it's displayed. The opportunity to feature this rare old Detroit iron and unique Minneapolis engineered drivetrain is a compliment to Truckin' magazine.
Napco History
At first glance this viper red '55 GMC pickup appears to be an aftermarket, lifted 4x4. But if you look closer you will notice the NAPCO badging on the fender. What is NAPCO? It stands for Northwestern Auto Parts Company. During the mid-'50s NAPCO started producing their Powr-Pak 4x4 conversion kits for OEM GMC and Chevrolet. Later, the Powr-Pak 4x4 kits were available for Ford and Studebaker trucks.
During the WWII years many automotive part companies focused their attention on projects commissioned by the United States government. During this time of war the parts and assemblies were tested on the largest proving ground on the planet, under extreme conditions. After the war, government priorities changed and NAPCO redirected its vast engineering and manufacturing experience to produce goods for private industry, which included the production of the famous NAPCO Powr-Pak 4x4 conversion.
There is some mention that NAPCO started producing 4x4 conversions for GM trucks as early as 1949. But it was not until October 28, 1954, that Chevrolet introduced the '55 1st Series. All of the NAPCO conversions were done on 3/4-ton and larger trucks. GMC and Chevrolet were the most popular conversions. (Later the NAPCO conversions were available for Ford, Studebaker, and other manufacturers.)
During 1955 NAPCO was very busy pushing its proven 4x4 conversion kits on truck upfitters and some of their GMC dealers across the country. That's why this '55 GMC is rare. Upfitters were companies that installed upgrades and accessories like winches, auxiliary transmissions, tandem drive axles, dump beds, and hydrovac systems on stock factory trucks. These NAPCO-enhanced vehicles were branded with the name "Mountain Goat" expressing their climbing abilities.
The NAPCO Powr-Pak 4x4 conversion kits were not available for GMC until 1956, then followed with Chevrolet in '57. 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 Chevrolet could only be ordered with the 235ci six-cylinder and a four-speed manual transmission.
The first "All GM" factory 4x4s were introduced in 1960 when both Chevrolet 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 four-wheel-drive specific chassis on the four-wheel-drive trucks. This was the beginning of the end for the 4x4 Powr-Pak conversion element of NAPCO. NAPCO did produce conversion kits for a few more years, but the main business shifted to the heavier trucks (1-1/2 ton and larger).
After a major 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 in 1961. It seems that since NAPCO was bought by DANA Corp it was pulled into its black hole during the merger or buyout of SPICER. Who knows?
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