Three Factory Muscle Cars Almost Nobody Sees: GNX, Yenko Camaro, Boss 429

Some factory muscle cars were built in small numbers on purpose. These three are the ones most gearheads never get to see in person, and each has a story behind it. 1987 Buick GNX Turbo […]

Some factory muscle cars were built in small numbers on purpose. These three are the ones most gearheads never get to see in person, and each has a story behind it.

1987 Buick GNX

Turbo V6 that Buick underrated at 276 horsepower

The GNX started as a Buick Grand National. McLaren Performance Technologies and ASC upgraded each one with a bigger turbo, a larger intercooler and a reworked transmission. Buick rated it at 276 horsepower, which was a very modest number for how hard it hit.

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Yenko Super Camaro

Dealer built 427 rated at 425 horsepower

Don Yenko ran a Chevrolet dealership in Canonsburg, Pennsylvania. He put Chevrolet’s 427 rated at 425 horsepower into Camaros, and in 1969 he used the factory COPO ordering system to get the engines installed. These cars are among the most collectible of the 1960s.

1970 Ford Mustang Boss 429

Semi-hemi 429 built to homologate for NASCAR, rated at 375 horsepower

Ford built the Boss 429 Mustang so its new semi-hemispherical 429 would qualify for NASCAR. The engine was so wide that Kar Kraft had to modify the front end of the car to fit it. It was advertised at 375 horsepower.

Image credits: 1970 Ford Mustang Boss 429.jpg by Simon Davison from Los Gatos, United States (CC BY 2.0) · 1970 Ford Boss 429 Mustang (26149503277).jpg by Bob P. B. (CC BY 2.0) · 68 Yenko Camaro.jpg by Dana Hurt (CC BY-SA 4.0) · Sloan Museum at Courtland Center December 2018 30 (1987 Buick GNX).jpg by Michael Barera (CC BY-SA 4.0). Facts from Wikipedia.

Which one would you park in your garage? Tell us in the comments.

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