Pontiac Firebird SD, Buick Grand National GNX, Mustang 5.0­-highlights of the muscle flexed in '70s and '80s Detroit


The American collectible car contingent has long argued over when the "real" cars stopped rolling out of Detroit. Collectible prices indicate Detroit's muscle atrophied with astonishing speed after 1971. What followed was a period of wheezy darkness that included 165-hp Corvettes, and it didn't fully recover until the horsepower wars of the 1990s.

Things were so bad by the late 1980s, that pavement-pounding '60s muscle cars were sought by the younger crowd, which was my generation. But time marches on, and much to my chagrin, I am no longer part of the younger crowd. So what will Gen X be looking for if they aren't nostalgic about true (pre-1972) muscle cars?

Slim pickings in post-'71 performance

The same forces that caused the demise of the muscle car also make for very slim pickings in post-1971 performance. Emissions and safety standards, insurance regulations, and the like all led to widespread dumbing down of any kind of performance cars. That being said, here are a few notable exceptions that are indeed becoming collectible as time marches on. This is not a comprehensive list, just some highlights:

The last hurrah in traditional muscle has to be considered the 1973-74 Pontiac Super Duty 455 Firebird Formula and Trans Am cars. The Super Duty (SD) engine package is an incredibly stout and understressed unit with a conservative 290-hp SAE net rating. Everything from the block to the carburetor was SD-specific.

I'd argue the point that these were the best-developed performance car with a carburetor of the emissions era. Not until electronic engine controls were brought into play did anybody have this kind of performance again. Net horsepower ratings aside, true output was much higher, and these were great performing cars. Want proof? SD cars could run mid-13-second quarter-mile times at over 100 mph right off the showroom floor. Those are numbers not even GM's own Corvette could better for almost two decades.

Combined with standard radial tires, a very competent suspension, decent brakes, and GM's seven years of F-Body chassis development, the SD Firebirds were one of the best performing cars to roll out of Detroit at the time. Factor in very low production numbers (252 total cars in '73; 943 in '74) and these are highly collectible. Figure $100,000 or so for a nice '73, and $60,000 or so for a nice '74. Add 50% for a 4-speed car in either year.

GNX was an instant classic

The next big news out of GM for modern muscle has to be the advent of the Buick Turbos. Starting in 1978, the lowly Buick Regal was fitted with a turbocharger, to limited effect, much like the Pontiac Turbo Trans Ams of a few years later. Despite terrible reviews, Buick kept at it, and by 1984, the turbo Regal got serious with the introduction of the Grand National. This 3.8-liter V6 with its big turbo became the definitive 1980's GM muscle car. By 1986, with the addition of an intercooler and much refinement, GNs had 235 hp and could run 0-60 mph in under seven seconds. Slow by today's standards, but certainly serious stuff in the mid-1980s.

Nineteen eighty-seven saw the introduction of the limited-production GNX, an $11,000 option package on the base GN and by far the most collectible GN of all. With just 547 produced, it was an "instant classic," with people fighting to pay over MSRP when new. Zero to 60 mph fell in the mid-five-second range, and the GNX delivered quarter-mile times in the mid-13s, equal to the best muscle cars of the '60s. This was earth-shattering performance in 1987, when even a new Corvette couldn't touch these numbers.

Today, "in the wrapper" low-mileage examples still surface, but beware of formerly abused examples with rolled-back odometers, modifications, or their special GNX-specific parts long since harvested and sold off. Though $29,900 when new, average examples with miles on them now trade for $50,000 or so, and I've seen flawless, undriven, mothballed cars sell for $100,000. Don't care for a GNX? Look for the best original '86-'87 GN you can find in the $35,000-$55,000 range.

5-liter Mustang a lot of bang for the buck

Probably the best-known-and the highest-production-late-model collectible is the ubiquitous 5-liter Fox-bodied Mustang of 1982-1993. Starting with the return of the GT package in 1982, by '83 Ford was offering a four-barrel "High Output" version with a 5-speed. In 1985, they raised the bar higher, with a new roller cam-equipped HO in the last year of engines with carburetors. Ford introduced the fuel-injected 5.0 in 1986, and it came with higher compression and even more grunt. For around $10,000 new, a 5-liter Mustang GT was a lot of bang for the buck.

Special editions for this generation included the 1984 GT-350, available in white with red stripes, but it offered performance in looks only. There was also the 1993 Cobra R, which saw just 107 examples built-all with GT40 cylinder heads, tweaked suspension and brakes, and deleted a/c, stereo, and back seat. The next generation of Mustangs, 1994-2004, brought more limited-edition versions. Another Cobra R appeared in 1995, this time with a 5.8-liter V8 and just 250 produced.

The most specialized of all the Mustang "specials" came in 2000, again called the Cobra R. Three-hundred of these barely street-legal race cars were hand-built by Ford with a 5.4-liter DOHC engine, 6-speed transmission, special suspension and brakes, and body modifications. As with other Cobra R variants, the 2000 edition also was bereft of any sound deadening, rear seat, radio, or air conditioning.

I've seen prices from $20,000 for nice 1993 Cobra Rs to $80,000 for a "brand new" 2000 Cobra R. Personally, as a child of the '80s who actually helped dealer-prep a brand new GT-350 at the local Ford dealer in 1984, I have often looked for a time-capsule '84-'87 5-liter stick-shift car to just shove in the corner. With great examples struggling to bring $15,000, I predict we will someday look back at these cars as the GTO of the 1980s. The 5-liter Mustangs made performance available to just about anybody with a job, and in the process, became the poster child for a new age of the pony car wars.

Will we ever be able to restore these computer controlled, plastic laden cars that were long in the tooth even when new? Most likely not. But there is no harm in finding a really great example and keeping it healthy for future generations. People enjoying today's horsepower renaissance have cars like the Pontiac SD Firebird, Buick GN, and Mustang 5.0 to thank for keeping the flame alive during some dark years in Detroit.

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