1970 Buick GS 455 Convertible

1970 was probably the pinnacle of the Muscle Car era, and the GS 455 from Buick has a parking spot near the pinnacle of Detroit muscle cars.

For the 1970 model year, GM finally relaxed its corporate prohibition on engines larger than 400 cubic inches in midsize cars, and so the motor under the hood of the Skylark-derived Gran Sport swole up from '69's 400cid size to a massive 455 cube torque monster. The base version of the 455 was (under)rated at 350 SAE gross horsepower and 510 foot-pounds of torque. Order the Stage 1 package and horsepower was bumped to 360.

It had a Rochester Quadrajet 4-barrel carb, a 10.0:1 compression ratio, a lumpy cam, a pair of functional cold-air intakes on the hood, and drank premium gasoline at a 12.5 mpg clip. In a test, Hot Rod Magazine referred to this as "acceptable fuel mileage". Truly the past was another country.

Hot Rod Magazine's test car, a '70 hardtop coupe with a 3-speed TurboHydramatic auto and a 3.64:1 limited slip rear end (also part of the Stage 1 package), cracked off zero-to-sixty runs in 6.4 seconds and managed a 14.4 second quarter at 96 mph. With a four-speed and the right rear end, '70 GS 455's were among the few cars of the era that would legit run in the 13s on street tires right off the showroom floor.

The Diplomat Blue '70 GS 455 convertible in the photos lacks the Stage 1 badging, meaning it's got the garden variety 350-horse big block. It was photographed in March of 2023 using a Canon EOS-1D Mark IV and EF 24-105mm f/4L zoom lens.