Fourteen. That is the number of 1970 Plymouth Hemi ‘Cuda convertibles documented to have been produced with a four-speed manual transmission. The rarity of this specific configuration — the most desirable variant of the most desirable muscle car of the muscle car era’s final peak year — has made it the auction record holder for American muscle cars and the reference point against which all other American performance car values are indexed.

The Mustang Dark Horse represents Ford’s attempt to produce a track-focused Mustang that is analytically justifiable rather than simply powerful in the way that American performance cars have traditionally satisfied their performance requirements. The 500-horsepower 5.0-liter Coyote V8 is carried over from the Mach 1 with specific modifications — a new flat-plane crankshaft that allows the engine to rev faster and produce a different sound character — and surrounded by chassis, suspension, and aerodynamic development that is serious enough to require explanation rather than simply impressive horsepower figures.

The Boss 429 exists because NASCAR’s rules required Ford to produce 500 road cars equipped with the 429 cubic inch engine it wanted to run at Daytona and Talladega. The engine — designed specifically for high-speed oval racing with a semi-hemispherical combustion chamber configuration that Ford called the Crescent chamber — needed a Mustang body around it to satisfy the homologation requirement. Ford called Kar Kraft, a Michigan-based specialty builder, and Kar Kraft cut the front shock towers of the standard Mustang body to fit the wide engine, moved the battery to the trunk, revised the front suspension geometry, and delivered approximately 859 cars in the 1969 model year and 499 in 1970.

The Dodge Charger Daytona is one of the more extreme objects ever to wear a manufacturer’s badge and a license plate simultaneously. The 18-inch aluminum nose cone that replaced the standard Charger’s front end was designed in a wind tunnel at the Lockheed facility in Burbank. The 23-inch rear wing — positioned high enough that the trunk lid could still open — was there not for aesthetics but because the aerodynamics of the standard Charger body at 200 miles per hour produced lift that made the car dangerously unstable. Chrysler’s engineers needed the downforce. They also needed to sell 500 examples to homologate the car for NASCAR. They built 503.

The 1970 model year was the last before emissions regulations, insurance industry pressure, and fuel economy concerns began the systematic reduction of American muscle car performance. Chevrolet, aware of what was coming, produced the 1970 Chevelle SS 454 in the full knowledge that it represented a high-water mark that would not be repeated. The LS6 engine variant — 454 cubic inches, solid lifters, high-compression heads, and a factory rating of 450 horsepower that was understood at the time to be conservative — was the most powerful engine Chevrolet offered in a passenger car in 1970 and arguably the most powerful engine Chevrolet has offered in a passenger car since.