7 Insane Factory Muscle Cars

In 1969, Chevrolet built a Camaro ZL1 with an all-aluminum 427 that cost more than the car it was bolted into. The engine option alone was around $4,160 on a Camaro with a base price of roughly $2,700. Only 69 of them were built and Chevy dealers who ordered them mostly wished they hadn't. But here's the question I want to answer today. What happens when a car company completely loses its mind, ignores the accountants, ignores the insurance industry, and builds something for the street that had no business being on the street? These are the factory muscle cars that went genuinely nuts, not the ones with a loud stripe and a mild 350, the ones where somebody inside a very large corporation signed a piece of paper they probably shouldn't have, seven of them counting down, and the last one is the most expensive American production car of its era. Let's get into it. Number 7. The 1970 Buick GSX Stage 1. Buick, in 1970, was the brand your dentist drove. Deep pile carpet, whisper-quiet ride, the automotive equivalent of a leather club chair. And then somebody in Flint decided the Skylark needed a 455 cubic inch V8 with a Stage 1 package on top and painted the whole thing satin yellow with a matte black hood stripe and a rear spoiler you could serve dinner on. The rated output was 360 horsepower, which was a number Buick appears to have written down while laughing. The real story was torque, 510 pound-feet at 2,800 rpm. That was the highest torque figure of any American production car until the mid-2000s, and it came out of an engine that was supposedly built for who wanted a comfortable ride to the golf club. Motor Trend tested one in 1970 and got a quarter mile in the 13.4-second range at just over 105 miles an hour, which put it ahead of nearly everything else on the road that year. Buick built 678 GSX cars for 1970, and you could have yours in satin yellow or Apollo white. That was it, two colors. The company that sold beige to America built a bright yellow Torque Monster and then only offered it in two shades. Our next pick weighs about the same as a modern hatchback and had roughly four times the power it should have. Number six, the 1968 Hurst Hemi Dart. Chrysler wanted to win super stock drag racing. The rules required a production car, so Chrysler's answer was to take the Dodge Dart, the sensible compact your aunt bought, and stuff a 426 Hemi into the engine bay, which does not fit. So they made it fit. Hurst Performance did the conversion work in Michigan. The shock towers were reworked, the battery went in the trunk, and the front fenders, hood, and doors were fiberglass, or acid dipped steel to save weight. The side windows were Chemcor lightweight glass. There was no backseat. There was no radio, no heater, and no sound deadening. The carpet was gone. You sat in a fiberglass Dodge A 100 van seat on runners because that was lighter than a Dart seat. Chrysler rated the engine at 425 horsepower, almost nobody believed that. Real output was widely reported to be well over 500. The car weighed around 3,000 pounds. They built roughly 80 of them, sold them through dealers with a note stating the car was not intended for street use, and delivered them in primer, no paint. You bought a car in primer from a Dodge dealer in 1968. Bill Grumpy Jenkins and Dick Landy ran cars in this class, and the quarter-mile times dropped into the ten-second range with tuning from a compact economy car body shell. Chrysler did the same trick with the Plymouth Barracuda that year, and between the two of them, they made superstock more or less unwinnable for anyone else. Our next entry didn't need a fiberglass body because it brought its own Number five, the 1969 Dodge Charger Daytona. NASCAR in 1969 was an arms race, and Ford was winning it. So Chrysler put a group of engineers, some of whom had genuine aerospace backgrounds, onto the problem of making a Charger cut through air. What came back was an 18-inch fiberglass nose cone and a rear wing standing 23 inches above the deck lid. Creative Industries in Detroit handled the nose cone and wing conversions, doing for the Daytona what CarCraft would do for Ford's boss, 429 the same year. The wing height is the part everyone argues about. The popular story is that it was tall so the trunk could open. Chrysler engineers, including John Poynter, have said over the years that the height was mostly about getting the wing into clean air above the turbulence coming off the roof, and the trunk clearance was a convenient side effect. Both things ended up being true, which is why the argument never dies. NASCAR's homologation rules meant Dodge had to build 500 road-going versions to sell to the public. They built 503, and they were an absolute nightmare to sell. Dealers discounted them. Some sat on lots into 1970. People thought they looked ridiculous, which, to be fair, they did. Then in March 1970, Buddy Baker took a Daytona around Talladega Super Speedway and became the first driver to officially lap a closed course at over 200 miles an hour. 200.447 to be exact. NASCAR effectively banned the aero cars for 1971 by restricting them to a 305-cubic-inch engine, which killed them off. The cars that couldn't be given away in 1970 now trade for well over a million dollars when they're Hemi-equipped. Our next pick is the one that caused the most trouble inside its own company. Number 4. The 1970 Chevrolet Chevelle SS454LS6. General Motors had a corporate rule. No engine larger than 400 cubic inches in an intermediate car. That rule held for years, and it's why the GTO and the Chevelle were fighting Mopar with one hand tied behind their backs. For 1970, GM dropped the rule. Chevrolet's response was the LS6, a 454-cubic-inch big block with four-bolt mains, forged steel crank, forged pistons, solid lifter cam, and an 800-cubic-feet-per-minute Holley on an aluminum intake. Compression was 11.25 to 1. The factory rating was 450 gross horsepower, and this is the important part. That was the highest horsepower rating Chevrolet had ever put on a production car window sticker, higher than any Corvette of the era. You could order it in a Chevelle SS, which was a midsize family coupe. CarCraft and Superstock magazine both ran quarter miles in the low 13S on street tires, and with slicks and headers, people were seeing high 12S straight off the showroom floor. Roughly 4,475 LS6 Chevelles were built for 1970, and then it was over. By 1971, GM had mandated lower compression across the range to run on unleaded fuel. The LS6 rating dropped to 425 and then disappeared from the Chevelle entirely. One model year. That was the whole run. Our next one is even rarer, and it was built specifically so Ford could put an engine in a car that didn't fit either. Number three, the 1969 Ford Mustang Boss 429. Ford developed the 429 semi-hemi engine for NASCAR Super Speedway Racing. To use it, they had to sell 500 road cars with the engine installed. The obvious choice was the Torino, which is what actually raced. Ford instead put it in the Mustang because the Mustang sold showroom traffic and the Torino didn't. Problem. The 429 was enormously wide, and the Mustang's shock towers were in the way. Ford handed the job to CarCraft in Brighton, Michigan. CarCraft moved the shock towers outward, lowered the front suspension, moved the battery to the trunk, and hand-built every single car. They fitted a functional hood scoop that was, at the time, the largest ever put on a production Mustang. The official rating was 375 horsepower at 5,200 revolutions per minute. That figure was, in the polite phrasing of the day, conservative. The engine was built with four-bolt mains, a forged crank, and aluminum heads with crescent-shaped combustion chambers. Real output was widely estimated north of 500 in race trim. Here's the joke. On the street, in stock form, the Boss 429 was slower than a Boss 302 in a lot of situations because the small holly and the mild hydraulic cam were tuned for high-rpm superspeedway running, not stoplight work. The Boss 302 was the one winning SCCA Trans-Am Championships. The 429 was built purely to Road Test magazine got a 14.09 quarter mile out of one. The car was built to legalize an engine, and the engine never even raced in the car it was sold in. Ford built 859 for 1969 and 499 for 1970. Every one of them lost Ford money. Our next pick is the one where a car company charged more for the engine than the car. Number two, the 1969 Chevrolet Camaro ZL1. This is the one I opened with. Vince Piggins ran Chevrolet's product promotion group, and he'd spent years finding creative ways around GM's ban on factory racing. His method was the Central Office Production Order System, or COPO. It was a paperwork channel meant for fleet orders, taxi cabs, and municipal vehicles. Piggins used it to build race cars. Don Yenko of Yenko Chevrolet in Cannonsburg, Pennsylvania, had already been exploiting the COPO system to order big block Camaros in volume, and his dealer orders helped prove the pathway that made the ZL1 possible. COPO 9560 was the ZL1, an all-aluminium 427 that weighed about the same as a small block, roughly 500 pounds. The aluminium block itself was cast by Winters Foundry, which is part of why GM could build something this exotic in production quantities. Open chamber heads, four-bolt mains, dry sump provisions, and a factory rating of 430 horsepower. Actual output on the dyno was reportedly closer to 550. Baldwin Motion, out of Baldwin, New York, another dealer tuner, in the same orbit as Gibb and Yenko, were running ZL1-based cars to similar effect on the East Coast. Fred Gibb, a Chevrolet dealer in Laharp, Illinois, is the man who made it happen. He ordered the first 50 to satisfy the NHRA production requirement for superstock. When the cars arrived, the invoices showed the ZL1 option adding around $4,160 to the price. A base Camaro was about $2,700, so a car that should have cost roughly $3,000 was now over $7,200 at a time when a Corvette started around $4,700. Gibb couldn't sell them. He asked Chevrolet to take some back, and reportedly Chevrolet redistributed them to other dealers. In total, 69 ZL1 Camaros were built. Dick Harrell, known in NHRA circles as Chevrolet, campaigned one and got it into the 11s with basic tuning and into the 10s with proper race prep. Today, a documented ZL1 Camaro sells for well over half a million dollars, and a genuine ZL1 engine on its own can bring six figures. Chevrolet built the most expensive Camaro in history and then had to beg dealers to take them. Which brings us to number one. The 1971 Plymouth Hemi Cuda Convertible. The 426 Hemi was already the halo engine. Dual quad carburettors, hemispherical heads, 425 horsepower on paper, and considerably more in reality. By 1971, it cost about $884 as an option. Insurance companies were refusing to policies on Hemi cars for anyone under 30, and emissions rules were closing in. The e-body Barracuda was in its third year of the shape. For 1971, Plymouth gave it the four headlight front end and those fender gills on the quarter panels, which nobody else was doing and which the market immediately rejected. Barracuda sales fell off a cliff. If you wanted a Hemi in a Barracuda as a convertible in 1971, you were ordering a car that cost close to $5,000 with options. That's more than a Cadillac Coupe de Ville cost to lease for a year. And you were buying a car with a solid lifter race engine that needed valve adjustments and fouled plugs if you drove it gently. 11 people did it. 11 Hemi Cuda convertibles were built for 1971. Two were exported, nine stayed in North America. It's generally accepted that all 11 survive, which is remarkable given how these cars were used. One of them, a 1971 car, sold at Mecham Kissimmee in 2014 for $3.5 million. Another has changed hands privately for figures reported to be higher. And here's what gets me. In 1971, that car sat on a dealer lot and people walked past it because the styling was weird, the insurance was crippling, and gas was about to get expensive. Plymouth killed the Hemi at the end of that model year. The last one rolled off the line and that was the end of the 426 in a street car for 32 years. Every single car on this list lost money. The Daytona was a punchline until Talladega, the ZL one, cost more than a Corvette. The Boss 429 was a homologation exercise for a race the engine ran in a different car and the Hemi Dart was sold in primer with van seats. None of it made business sense, which is exactly why we're still talking about them and why the accountants eventually won and this era ended. So here's what I want to know. Which one of these would you actually daily drive, knowing what they're like to live with? The GSX is probably the sensible answer, but I have a feeling most of you are going to say the Hemi Dart. And I'd love to hear you justify that in the comments. And more importantly, what story about cars do you want me to cover next? Let me know down in the comments and remember to subscribe and hit like if you enjoyed this one. I'll see you in the next video.