Tough Mudder: 1956 GMC 100 Series NAPCO 4×4


Here’s one for you tough truck fans, it’s a 1956 GMC 100 Series NAPCO 4×4 and it’s listed on eBay with 5 days left to get your bids in. The current bid price is just over $4,500 and there is no reserve! These trucks can easily sell for $50,000+ when they’re restored. This uncut diamond is in Canyon Creek, Montana, just 25 miles northwest of the beautiful state capital of Helena.


We probably all know that NAPCO (Northwestern Auto Parts Company) manufactured 4×4 kits for Studebaker, Ford, Chevrolet, and GMC pickups. They were available directly from General Motors from 1956 to 1959 for between $1,200 and $1,500 factory-installed. Before that, from 1942 to 1956, customers could order a NAPCO 4×4 kit for just under $1,000 and it would bolt on in just three hours! I can’t make toast in three hours.


This truck has been in the Big Sky State since it was purchased new at Hulett Motors in Chester, Montana. It hasn’t been registered since the 1960s (!) and has been on the same ranch since then doing what it was made to do: chores. This is one tough mudder. The bed is well used as you can see from this photo but, like anything and everything, that can be fixed. There is some rust, of course, and it sounds like this truck has been parked outside so I can’t believe that there isn’t even more rust than there is. Hopefully mice haven’t gotten their evil little hands (hands?!) into anything with it being parked outside for so many decades.


The interior won’t get you access to the Amelia Island Concours anytime soon, but it could be brought back to like new again if that was your goal. It looks solid and that metal dash isn’t going to crack in the sun any time soon. The headliner looks good and check out that particle board sun visor! You’ll never see a Kardashian driving this truck, which makes it worth almost any amount of money to me.


The seller says that this drivetrain is complete and is ready for a mechanical restoration. Unfortunately, it “hasn’t been started in years” so prepare for the worst here. But, at least it turns over. They mention that the “original Pontiac V8” turned over and they stopped so as to not damage anything. I’m assuming that they mean that the 316 cubic inch V8 with 180 hp was manufactured in Pontiac, Michigan, not that it’s a Pontiac V8. Judging by the first few numbers of the VIN it’s a 102 (123.25 inch wheelbase) with a V8 and was manufactured in Pontiac, Michigan. I’m not sure why they crossed out the last numbers and didn’t list those. What do you think of this truck? Can it be brought back to life? I think that it can be, and this could easily be a $50,000-$75,000 truck when it’s restored, maybe more with the factory V8. Would you restore this one or get it working and drive it as it looks now?


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  1. Anthony Rodrigues

    GMC trucks did come with Pontiac V8 engines in the 56 – 57 era

    Like 2
  2. jmacc

    Was parked mostly facing west, I assume.


    my dad had a 1957 chevrolet pickup with a 265 power pack motor and a 1955 olds hydramatic transmission and an old acquaintance had a same year gmc pickup with a pontiac engine of unknown displacement and the same 1955 olds hydramatic transmission and each truck had the badge on the door with the huge “v” and the words hydramatic

    one tough transmission and i ought to know i did not cut it any slack and in case you are wondering, yes it parked in reverse it was a ’55

    • Dan Adams

      If you where low on the correct Tranny Fluid, You could put 30 Wright Engine Oil in it, then flush it out and put the right stuff in! – Plus The Hydromatic trans. just like the late 50s Powergluide trans. Cars and Trucks could be either Pushed or Pulled up to I think 25 to 35 MPH to jump start them if your battery was dead! – That sure would not work on todays rubber bumper cars & over priced tin & plastic trucks

  4. Jeffro

    The redneck in me just loves a ole truck, but I’d be torn to restore or drive as is.

  5. jeff6599

    Pontiac V8s were used in GMC trucks when something more powerful than their 6 was needed. They were options in 1955, 1956 and 1957 using the then current Pontiac displacement. They certainly whupped the Chevs, Fords and Dodges of the day all of which had displacements considerably smaller in their V8 offerings

    Like 1
  6. geomechs geomechs Member

    The Pontiac-sourced V8 was used from ’55 to ’59. GMC used its in-house V-6 after that. I actually like that Pontiac motor; one very tough engine to say the least. Of course in this application the 270 inline six wouldn’t have fallen far behind, unless you were travelling down the freeway; it was a stump-puller. I like what I see. Damn, I hate it when something like this shows up practically in my own backyard–only a hop, skip and a jump away. I’m sure I’d be sleeping in the grandkids’ playhouse in the backyard if I showed up with this truck in tow. But I think I’d fare out a lot better with this than I would if I came home with a station wagon.

    I see this truck was sold new in Chester, which is about 50 miles east of Shelby, along US-2. It’s interesting how, not too long ago, Chester was a bustling town–a little over a thousand people at one time. The Big Three were well represented with sizeable dealerships, and at least 3 major manufacturers of farm machinery were sold out of there. Now the shops are closed; well the Ford dealership is a car museum/car club meeting house, which is a neat place to visit. Everyone drives to Havre to do business nowadays…

  7. JW

    I don’t care what it would be worth restored to showroom condition as I would restore it to drivable condition with a decent paint job, make the interior presentable and comfy, drivetrain reliable and brakes sound then use it for it’s intended purpose. I love it.

  8. Howard A Member

    These GMC’s were just dripping with testosterone. When there really was a difference between a Chevy and a GMC. Too bad it doesn’t have the chrome grill, but still, just looks mean. I think this goes a bit overboard with the patina thing, these are such nice looking trucks, I’d paint it ( and a basic color, they didn’t have 90 coats of candy red in ’56, on pickups anyway) GMC gauges were cool too, but make no mistake, and JW is right, these were a bear to drive ( and stop, for that matter) They certainly weren’t meant for barreling down the boulevard at 75 mph, more like over rough terrain at 7.5 mph. A $1,000 dollar conversion doesn’t sound like a lot today, but in 1956, that was equal to about $8,800 dollars today, so it had better be needed. Very few were sold, to the public, anyway. That back bumper is consistent with municipal trucks I’ve been around, so I’m sure that’s who had this. Great find, but like most else that comes through here, out of my league.

    Like 1
    • geomechs geomechs Member

      Hi Howard. Totally agree with you on the repaint idea. I also agree with the rough terrain at 7.5 mph. A lot of local ranchers went to trucks like this in the later 50s; the surplus Jeeps left much to be desired and the full-sized Jeeps didn’t fare out a lot better. By the mid-60s theses trucks were everywhere…

      Like 1
      • Howard A Member

        Hi geomechs, perhaps out west, but we never saw 4 wheel drive anything in the big city when I was a kid. It didn’t take long for rural customers to know the advantages of 4 wheel drive, and not that tin can Willys either. In the city, however, for the old man, it was a set of “Town and Country’s” and 2 cinder blocks in the back of the Olds sedan( not that they needed more weight) all through the ’60’s. He even had a set of “studded snow tires”, until they were banned. Fact is, I don’t even remember seeing 4×4 pickups until into the early ’70’s. Every pickup truck was 2 wheel drive.

      • geomechs geomechs Member

        The traction in the back was a good idea. I knew a lot of guys who simply filled the beds of their pickups completely with snow. Since we used our trucks to haul things, we resorted to other means: Filling pieces of inner tubes with sand then tying up the ends to make them look like black sausages; sacks of wheat (which got damp and sprouted; my favorite, a couple of cracked John Deere 5020 cylinder heads; engine blocks; concrete blocks; even an old anvil (till someone stole it). Studded tires, I almost forgot about those….

    • Ck

      Hey Howard,I totally agree with you on this one. Whoever buys this truck needs to get some paint on this thing! Original color of course .I know it looks good the way it is ,but there aren’t that many of these trucks left out there. This old girl needs to be restored back to the way she was back in 1956.

  9. Glen

    Get it usable, have fun, then if you can afford it, (or complete it yourself) give it a proper restoration and sell it.

  10. Clinton

    I’m pretty sure I need this truck. If I had some money I’d be all over it. Someone wanna loan me some money? In the mean time lotto tickets it is lol.

  11. Scotty Gilbertson Staff

    Auction update: this truck sold for $8,056.

  12. Jeffrey Duddles

    Costly conversion: $1,500.00 in 1956 had the same buying power as $13,238.34 in 2016.

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