10 Astounding Things You Probably Never Knew About US Muscle Cars

Updated March 17, 2017

Americans have a thing for speed. This is quite evident in the 1960s and 1970s production of wild and quite rare muscle cars that had giant V8 engines with powerful torques. The 1980s introduced more powerful machines capable of faster speeds and more compatible with the then stringent emission controls. Behind the massive horsepower and speed stats of these cars, there were some surprising stories too. Let’s take a quick peek at some of the most interesting facts you may never have known about American muscle cars.

10. The 1968 Ford Mustang Shelby GT500


As any Mustang purist would tell you, Carroll Shelby’s first two years were quite admirable. We are talking about the simple styled, light, and track-perfect GT 350s of the 1965 and 1966 period. Models that came later in ’67 and ’68 provided greater fun in terms of performance and were also the top choice for anyone who ever dared venture into the drag race arena.

For the first time, the 1967 and 1968 Shelbys GT 500 featured 355 horsepower provided by 428 cubic inch block engines. Car analysts of those days saw, for the first time, quarter-mile runs in mid-to-low 14 second laps which were quite fast by the standards that existed back then. The Shelby Mustangs had flashier styles than the older cars, mainly because of the new found power and increased torque. The quicker and high performing King of the Road (KR) model had already hit the race track by 1968 too.

What you probably didn’t know: The ’67 Shelby Mustangs had mercury Cougar tail lamps but the ’68 models featured lamps modified from the 1966 Ford Thunderbird.

9. 1984 Chevy Corvette


The Corvette, a 3rd generation American sports car, had a very long reign that began in 1968 and extended all the way to 1982. When GM was launching the next-gen C4 Corvette, every car enthusiast back then had their own wild speculation about what the car would look and feel like. While some predicted a mid-engine chassis similar to those found in exotic Italian models, others believed it would be a rotary engine similar to Mazda’s.

When it came out, the Corvette wasn’t as radical as expected. It maintained the same small block Chevy V8 engine driving the rear wheels. It had a meager output of 205 horsepower. Years later, the engine was endowed with a better tuned fuel injection system that boosted horsepower and performance. After five years, Chevrolet launched its ultra-performance Corvette, the ZR-1 which was capable of delivering 375 horsepower.

What many probably never knew: No Corvette was ever manufactured in 1983. The third-generation Corvettes were produced in 1982, but Chevy had to wait until ’84 to launch the all-new high-performance car. There were many reasons for the delay. Some experts in car matters claim the delay was occasioned by tighter emissions regulations that called for further development and refinement, while others state that there were quality glitches in the factory. All we can authoritatively say is that for some reason all the 1983 Corvette prototypes were destroyed, except one. It is a white car that can be found now at the National Corvette Museum in Bowling Green, Ky.

8. 1969 Dodge Charger Daytona


As any real muscle car enthusiast of yester years would tell you, the 1969 Dodge Daytona and its close relative the 1970 Plymouth Superbird are without doubt the most radical rides to emerge from the muscle car rivalry back then. Just like its name suggests, the Daytona was not made for street racing. It was designed for NASCAR races on the longest and fastest superspeed tracks.

To improve its top speed, the car’s engineers gave it a wind tunnel treatment. The big Dodge received quite a number of aerodynamic modifications which included a flush back window, a 2-feet long rear wing, and a new longer sloped nose cone. What came out was nothing short of impressive. It became the first car to break the 200 mph record in NASCAR history. After many victorious runs in 1969 and 1970 by Dodge and its sibling the Plymouth, NASCAR came up with new rules that banned both cars from their races. The two cars, which came with the famous 426 Hemi and 440 big block engines are some of the most sought-after cars today and cost over $150,000 in car auctions.

What you probably never knew: Compared to a standard Charger, the aerodynamic modifications done on the Daytona lowered its coefficient of drag to 0.28, which was quite impressive even by the current standards. However, did the rear wing have to be that huge and tall to increase rear end downforce? Not really. Legend has it that the wing was made with an exaggerated height to make it possible for the trunklid on the car to pass underneath while fully open.


7. 1970 Oldsmobile 442


Why name this car 442? Because it came with a 4 barrel carburetor, a manual 4-speed system, and 2 exhausts. Its design was borrowed from the Cutlass but it was a hot muscle feat of engineering from Oldsmobile. The 442 was a contemporary of two other GM greats, the Pontiac GTO and the Chevrolet Chevelle SS. Similar to the GTO, the 442 was actually a trim level car in the beginning but by 1970 it featured a massive 455 cubic inch V8 engine equipped with the best W30 parts and could deliver 360 horsepower and 500 pound-feet of torque. It did 0 to 60 in slightly less than 6 seconds which was quite an achievement for an Olds back then.

What you probably didn’t know: James Garner, the famous actor, took a 1970 Olds 442 to the NORRA Mexico 1000 race, which later became Baja 1000, and won second place. The car, fondly known as Goodyear Grabber, was made by Vic Hickey, the renowned Baja-race car guru, under the sponsorship of Goodyear tires. The car has recently been restored and put up for auction.


6. 1978 Pontiac Firebird Trans Am


The late 1970s muscle cars were a shadow of the earlier years’ models. Increasing emissions controls, hiking gas prices, and rising insurance costs made many car manufacturers to cut back on horsepower. However, Pontiac continued producing high-performance cars regardless of the changing environment. Since its starring role in the Smokey and the Bandit movie, the Trans Am had become a popular choice in the muscle car industry. To add to this popularity, Pontiac increased the car’s horsepower from 200 to 220. They also gave it a special package known as WS6 in auto engineering circles that included wider 8 inch wheels, sport-tuned suspension, and a faster steering wheel. The resulting Trans Am was faster and easier to handle than the Corvette.

What you probably didn’t know: In 1976, the Pontiac had a T-top roof that came close to what you could find in a convertible Trans Am. The roof section which could be lifted up was designed and made by a company known as Hurst, which is why many called the lift-up roof a Hurst Hatch. They had one major problem, they leaked. This made Pontiac to create their T-tops in collaboration with GM’s Fisher. The new T-top came in the 1978 model. Some 1978 Firebirds have Hurst T-tops while others have the Fisher version. You can tell the difference by the size of the roof panels. Fisher T-tops have larger glass panels than the Hurst Hatch versions.


5. 1969 Ford Mustang Boss 429


NASCAR’s golden age began in the late 1960s and extended to the early 70s. Stock-car racing was a serious business for many car manufacturers. It was a time when automakers dreamt up all types of engines and bodywork designs meant for racing. A car manufacturer just needed to sell 500 of these radical cars to feature them in NASCAR.

One of the beasts made in such a fashion was the Boss Mustang. It never competed in NASCAR, but it was quite powerful with a 429 cubic inch V8 engine that could deliver 375 horsepower. It could rev up to 6000 rpm. It was designed for the racetrack. The car’s major drawback was its poor performance on the street because it ran slower than other Mustangs that came with bigger block engines at the time. The V8 engine was too large to fit in the stock Mustang’s engine space. To solve the problem, Ford contracted Kar Kraft, a Brighten, Michigan, based auto company, to rectify the problem. Kar Kraft changed the car’s shock towers placement, sent the battery to the trunk, and widened the front end track. All these modifications were done to make room for the large engine. The Boss 429 is such a rare car today that it can fetch more than $200,000 at car auctions.

What you probably didn’t know: Between 1969 and 1970, there were three different engines fitted in the Boss 429. The first was the S-Code fitted in the first cars, followed by the T-Code that had lighter parts and finally the A-Code that came with the last cars in the 429 line.


4. 1970 Chevy Chevelle LS6


After GM finally allowed midsize cars to be fitted with engines bigger than 400 cubic inches, it created a frenzy of muscle car production. Oldsmobile gave its 442 model a 455 cubic inch engine while Chevy installed a massive 454 cubic inch V8 engine to its Chevelle SS.

The L6’s power output is estimated at 450 horsepower and 500 pound feet of torque. With a high compression ratio and a bigger Holley 780 CFM carburetor, the car had a significantly higher output. Experts claim that the L6 has the highest hp rating of all muscle cars.

Interesting fact: The Chevy Corvette is the company’s best performance car. However, the planned LS7 that was said to have 465 hp would have rivaled the L6, but it was never released to the public.


3. 1969 Pontiac GTO Judge


Pontiac was the reigning king of muscle cars in the early 60s. One of its most significant breeds was the 1964 Pontiac GTO. Come 1968 the car was facing fierce competition from new entrants. The company began contemplating on how to make cheaper versions of the car fitted with smaller 350 cubic inch engines. However, the idea didn’t go down well with the company’s boss, John DeLorean, who decided to have the company make another version of the car that was better than the regular GTO. DeLorean named it Judge. It featured a 360 horsepower Ram Air III engine as a standard but buyers could go for an optional Ram Air IV engine that had an output of 370 horsepower. GTO Judge Ram Air IV convertibles are quite rare to find today because there were only 5 made in 1969.

Interesting fact: The Judge was so popular that the lead singer of the rock band Paul Revere and the Raiders wrote a song about it. In fact, the first TV commercial for the car featured the band singing about the car. It is one of the first rock music videos made.


2. 1969 COPO Camaro


There is a department of Chevy known as the Central Office Production Order (COPO) that deals exclusively with the company’s fleet sales. The COPO was meant to oversee production of heavy-duty suspensions for police cars and taxi cab interiors that were stain proof. Other enterprising dealers including Pennyslvania’s Yenko Chevrolet also thought their Camaros could benefit from similar modifications too.

COPO’s order 9561 made specifications for a 427 cubic inch V8 engine similar to the Corvette with 425 horsepower. The rarest of them is the COPO specified all-aluminum V8 engine of the ZL-1. It has 5 additional hp and is a race-spec engine with an output of 550. There were only 69 ZL-1 Camaros made which makes it so rare that one can fetch more than $400,000 at a car auction today.

Interesting fact: The all-aluminum ZL-1 V8 made according to COPO 9560 order is an engine made for racing. Chevy developed the engine originally for the Chaparral team to use in the An Am series. However, you can hardly tell the difference from outside, because the ZL-1 has no specific emblems, just the usual Camaro badge.


1. 1987 Buick GNX


After the big block V8 muscle cars of the 60s and 70s had come and gone, Buick thought of bringing back the muscle car magic in the 80s. They built the Buick GNX that came with a turbocharged V-6 engine. It was based on the Grand National model but had a power improvement from the Grand National’s 245 to 276 hp. One of the GNXs was tested by Car and Driver in 1987 and found to go from 0 to 60 in 4.6 seconds. It became one of the fastest cars of the time. There were only 547 of such machines made.

Interesting fact: There were several of these engines left when Buick halted production of the GNX. Pontiac took some of them and fitted them in the 1989 Trans Am released on the company’s 20th anniversary. The V-6 was rated at only 250 horsepower, but real GM fans knew the true power that resided under the Trans Am’s hood.




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