Muscle Car Atrophy: 5 Classics That Lost Value This Summer

If you’ve been following the market for collectibles for any length of time, it’s pretty obvious that the world isn’t what it used to be just a couple years ago. From Rolexes to the art market, and NFTs to sneakers, a distinct cooling effect has settled everything. It’s not so different in the collector car market, which has experienced its own ups and downs over the past four years. However, the classic car market is more mature than it once was, with a more solid enthusiast foundation compared to periods of previous swings.

Those of us who have been around for a while remember the biggest effect of the last memorable market swing, which impacted muscle car values more than other segments. The 2008 recession saw values of many cars wiped out in a matter of months, with a slow, years-long recovery that followed. The last upswing of 2021–22 saw muscle cars benefit again; thankfully, the most recent cooling effect has been less severe than it was in ’08, and we have observed a soft landing for values. All in all, the biggest swings in value have primarily occurred at the top end with the most exclusive muscle cars. There have been exceptions, however; market leaders such as Hemi Mopars haven’t moved much since spring. Let’s look at some of the biggest changes in the muscle car market and decipher what is going on.

1968–72 Chevrolet Chevelle SS: -6 percent

GM hit its stride in styling and performance with the redesigned A-body in 1968. More refined lines and increasing horsepower figures helped define the 1968–72 Chevelle, Olds 4-4-2, Pontiac GTO, and Buick GS as pinnacle years for GM muscle. While brand loyalties exist within the umbrella of GM fans, it is hard to deny that the Chevelle SS reigns supreme as the most recognizable. These cars looked tough and they had the muscle to back it up. Peaking in all out performance, the 1970 LS6 Chevelle, with its 454-cid big-block V-8, would lay claim to the highest advertised output—450 horsepower—a figure that would stand for decades, until the horsepower wars of the 2010s and beyond.

As is the case with most top-tier cars, the LS6-equipped Chevelles fared the best as values increased, but as the market has calmed, they have also dropped the most within the Chevelle market, at an average of six percent for coupes. The remainder of Chevelle Super Sports, however, were not untouched. A more moderate drop of around three percent occurred across most non-LS6 454 and 396 cars. This is far less meaningful than the drop of the top-tier model, but it’s an indication that more than just the big cars are stepping back. What this means for the future is that as the market continues to gradually cool, so too could Chevelle values as the we find new equilibrium.

1969–70 Ford Mustang Boss 429: -7 percent

Ford’s “Boss Nine” is perhaps the ultimate expression of the Ford Mustang as a sheer powerhouse of a pony car. As the story goes, Ford needed to homologate its semi-hemispherical-headed 429 for NASCAR competition, so the Mustang was chosen as the chassis to produce the number of 429-equipped cars to meet minimum production requirements. The problem with the 429 engine, however, was the fact that it was too large to fit in the standard car, so off it went to Kar Kraft, which already had experience shoehorning the 427 FE into the GT40 a few years before. Despite the effort needed to prep these Mustangs, Ford managed to turn out a total of 1358 of them.

Boss Nines have become quite sought after as blue-chip collector cars, making them some of the most valuable Mustangs of the era, alongside Carroll Shelby’s creations. Looking at the past few months, the Boss walked back its values by an average of seven percent. While top-tier cars rarely see their values sit stagnant, this is a noteworthy drop. Much of this has to do with poor market performance after the spring. Drops were not isolated to the Boss; other performance models of the era such as Mach 1s stepped back an average of 4 percent. It’s important to remember that these cars experinced rapid growth a couple years back, and eventually the market finds equilibrium. We’ll need to stay tuned a while longer to see just how much change is in store.

1967 Shelby GT500: -6 percent

Ford’s first update to the massively successful Mustang came in 1967, with more aggressive looks and enough room in the engine bay for the larger FE series engine. Following on the formula of taking the standard Mustang and improving it further, Shelby American seized on the opportunity to show the world what the platform could really do. Dropping in a Police Interceptor 428 and warming it over meant that at 355 horsepower, this would be the wildest Mustang to date. And, with unique styling and the GT500 nameplate, a legend was born. Adding to the already-exclusive nature of Shelby ownership, 1967 would be the last time all upgrades were done at Shelby American, making these the last truly Shelby-built Mustangs.

These GT500s are highly sought after and coveted by collectors to the point they occupy a special place in the Shelby market. While later models fared fine, neither gaining or losting value, 1967s have stumbled a bit. Losing six percent over the past quarter, this was the result of some weak prices being posted earlier in the summer. Although it is too early to call this any sort of continuing trend, these high-profile cars are certainly a leading indicator of the health of the muscle market.

1969–72 Pontiac Grand Prix: -4 percent

Technically, the Grand Prix falls in the personal luxury category, but we’re going to include it here anyway. And while the GP may have had a focus on comfort, even Pontiac in 1970 said in its marketing: “We don’t build a ‘luxury’ car. We build a performance car, then we make it luxurious.” If we peek under the sheetmetal, you’ll see that Pontiac delivered on this promise. The new G-body platform that the 1969 GP and 1970 Monte Carlo sat upon was really just an A-body–derived frame shared by the LeMans. Under the hood was a standard 350-horsepower, 400-cid engine yanked straight from the GTO. Yeah, these things could scoot.

So now that we’ve made a case for the Grand Prix as a muscle car, let’s dig into how these have done. The fact remains, unless you know what these cars really are capable of, they fly under the radar for the average muscle-car enthusiast. That said, they have gradually crept up in value over the past several years, putting up decent numbers when a great example comes to market—a pristine 400/350-equipped car could fetch more than $40,000. That said, though there are staunch enthusiasts of these cars (your author included), there aren’t enough to keep the values way up. Crucially, mainstream parts support isn’t quite there compared with the LeMans and GTO that share so many underpinnings. The result is that while the GP is down by four percent when averaged out, condition #3 (good) and #4 (fair) cars fell by 12 percent—an indication that cars needing work have become harder to sell. This is a trend we’ve seen play out across the market: Buyers want sorted cars they can use now instead of cars that need attention. The GP has just fallen victim to that sentiment more than others.

1969–70 Pontiac GTO Judge: -6 percent

Conceived to compete with Plymouth’s successful Road Runner, Pontiac introduced a flashier and hip package to the GTO for 1969 to try to claw back some market share. Named after a comedy routine from Rowan & Martin’s Laugh-In, a popular TV show at the time, “The Judge” was a lot more than just a flashy appearance package to entice the youth to plop down their hard-earned cash on a GTO. While bright colors, graphics, and spoilers were certainly attention-grabbing, Pontiac stayed true to its commitment of delivering a real performance car by making the upgraded Ram Air III 400 engine standard in the Judge, with the more potent Ram Air IV available as an option.

These are among the most sought-after Pontiacs, period. Not only did Pontiac nail the performance aspect, but GTO Judges are arguably some of the best-looking muscle cars to come out of Detroit during the era. The Judge also has the distinction of carrying some of the biggest fluctuations of the muscle car market this past quarter. Soft showings mean that 1969 Judge coupes dropped by nine percent on average, while the 1970 dropped by an average of just three percent. Before we panic, it’s important to remember that these cars experienced huge growth a little over a year ago, and these drops haven’t fully erased those gains. It is, however, an indication that this segment is searching for new footing after some big increases.