The Mystery Concept Is More Mysterious Than Ever – We May Never Know Exactly What It Is

We’re such suckers! Here we thought we had this 1976 GM Mystery Concept all figured out. I accepted Jim Cavanaugh’s rational deduction/guess of a design concept for the upcoming gen2 Isuzu Faster/Pup/LUV as logical; at least more than any of the others. I did continue to have some serious nagging doubts, as it was looking more full-sized to me and the rear spring hanger is actually quite different than the one on the Isuzu. Frankly, I was just getting a bit eager to see the whole episode go away. I don’t like being stumped, and I’ve never been this stumped.

But CC’s Don Andreina wasn’t satisfied with that outcome, and contacted the GM Heritage Center to ask if they had more shots and any info. And what they sent back makes it certain that Jim’s guess is way off base. You’re going to have to send that prize back, Jim.

As soon as I (and Don) saw this shot, it was 100% obvious that this was not a styling exercise or concept, or ever came out of the GM design Center. Nothing like this utterly generic front would ever have been done there. The setting is all wrong too; a crude floor and curtains.

And that was confirmed by the response Don got from MGHC:

Hi Don,

Here are 2 contact sheets of 8 photos of the truck from our database and
a reply from a retiree from GM Truck Design.

Definitely not at design staff.. looks like something that might have
been done at Fisher Body or Chevrolet engineering.. don’t remember ever
seeing that…door frame and windshield from the 1967-72 truck, rear
bumper from a 73 truck.. my guess would be a 2 door Blazer concept using
the longer wheelbase and overhang of the Suburban chassis. Probably a
clinic / engineering evaluation model showing a lift glass and mini drop
gate concept that never made it to production.

Yes, definitely not at design staff. And yes, possibly done at Fisher Body or Chevrolet Engineering. But I can’t agree with the rest of it. The door frame and windshield are definitely not from the ’67-’72 truck, or any other production truck. I absolutely ruled that out by careful examination. And it’s definitely not sitting on a Suburban or Chevy pickup chassis. The rear springs are totally wrong for that. And that alone is a big part of the mystery. As well as why all of the rest of the truck is unique, and not just a redone Chevy Blazer, Suburban or pickup.

So there’s the part about the tailgate. Yes, it’s not a stock tailgate as used on the Blazer or Suburban. Even the bumper isn’t from a Blazer or Suburban, although its pretty close. But not close enough, so they made a new bumper that looks similar but is slightly different. Makes sense. And look at that front wheel negative camber. I’ll bet there’s no front suspension up there at all. And the rear spring are looking like they’re not even be attached to that “axle”. Dummies. I suspect the frame is just two straight rails to mount the body to, and the axles are rigidly attached to it.  And the handle on the rear hatch is drooping. Dummy indeed. The only items we can be reasonably sure about as being from the GM parts bin are the wheel covers, and maybe the door latches. Maybe not.


The highly innovative tailgate has an 80/20 split, with a mini-tailgate and a large hatch above it. Seems kinda’ dumb to me. What possible advantage would it have over the stock tailgate and hatch?


Here’s the tailgate down and the hatch closed.

Don also buys into it being an engineering/body exercise for the purpose of evaluating the new tailgate design:

My opinion; an engineering study purely for the feasibility of the rear hatch, nothing to do with current GM models – deliberately anonymous. Note the pockmarked surfacing on the front fender, this was a no-budget (for GM) effort – maybe even only produced for an internal clinic, but more likely for some outside testing. Total parts-bin effort with a hint of 67/72. That face says everything about how this is not a Styling job

Well, it’s about as good as any explanation. But it’s still highly unsatisfactory. If the body/engineering folks wanted to evaluate a new tailgate design, why the hell would they create a complete new dummy vehicle to do so? Yes it is a dummy, as it has no hood opening whatsoever, and I’m now totally convinced that the chassis is a dummy too.

Why not just use a production Blazer or Suburban for this purpose? That would make 1000 times more sense than building a fiberglass dummy vehicle to evaluate a tailgate. And why build it as a long wheelbase version, when that didn’t seem at all a viable concept, given that the four door Suburban was a much more practical configuration. And build a tailgate with that odd and impractical 80/20 split?

Don thought perhaps this might have been built to test the overall lwb/Blazer concept at a clinic:

Further to that. If this was to be shown in a clinic, they might have deliberately anonymised it as is sometimes done – hence not using a real C/K.

Well, there’s a problem with that line of thinking. When the Big Three test concepts at consumer clinics, the vehicles are finished inside and out to look production-ready. They might lack badges, but they have to be attractive and nicely detailed, otherwise how would anyone compare this to an existing Blazer, Suburban or Bronco? it looks like something from Romania, back then.


Look at the interior of this. It looks military-grade. Primitive, crude, and absolutely not something that GM would consider showing at a consumer clinic. Yuck!! But it’s not military, as per the carpet in the back as well as so many other signs to the contrary.

And again, what’s so odd is that the Suburban had a similar interior configuration, in how its middle seat folded down. But I’ve compared the two, and there are zero recognizable Suburban parts here. And look at that folding front seat.  They could have used the Suburban’s middle seat, which also has a split and folds up on the right side to give access to its third seat. But the backrest split on the Suburban is roughly 70/30, meaning two folks could be sitting on it while the right portion folds up. This split is more like 60/40, and again looks crudely put together. Look how high it lifts up. Who knows what that metallic handle is for? And the left side of the seat has a decided tilt to it.

It all looks more than a bit like a wagon from the late 40s or early 50s, except for the carpeting.

Although the Suburban’s spare tire is mounted in the same general area, its spare is significantly lower, partly recessed in a well in the floor.

A completely new dummy truck, nothing apparently shared with a production Blazer or Suburban, except its general size (I’m now quite certain it’s not Isuzu-sized, as some significant general proportions/sizes don’t jive).

So what is this?

I’m totally stumped, probably because I’m too logical. Why would some division at GM build a lwb “Blazer” concept with a silly tailgate, and build a complete fiberglass (presumably) body and interior, and not use a real Blazer as a starting point? Or even any parts? It makes absolutely no sense.

Here’s the best thing I can come up with: it was simply an exercise given to a group of new hires/trainees to teach them skills in this kind of work. But that still doesn’t make sense. It’s just too crude for mid-late 70s standards. Why would you teach them that?

Does anyone have a better answer? I sure hope so.