The Buick Gran Sport was launched in 1964 as Buick’s answer to the Pontiac GTO. By 1968 it was on its second-generation body that would carry it through 1972, and the end of mainstream muscle.

The 1968 Buick GS was based on a Skylark Custom and available with a 350-cid V-8 with 4-barrel and 280 horsepower. It offered three- and four-speed manual transmissions and two-speed automatic transmission. The California GS added a vinyl roof and was only available with an automatic transmission.

The GS 400 offered the 340-horsepower, 400-cid V-8 and was available in coupe and convertible. Three- and four-speed manual transmissions were offered along with a three-speed Turbo Hydra-Matic automatic transmission. Cold-air Stage I and Stage II induction was available from January 1968, and was the performance option of choice. A Stage I equipped GS 400 could run to 60 mph from a stop in 7.5 seconds.

In 1969 the GS 400 wore a different hood with cold-air induction, and the Stage I and Stage II packages offered serious performance. The Stage I made 345 hp and came with Posi-traction, optional disc brakes and heavy-duty suspension. More impressively, the car’s engine generated 440 ft-lb of low-end torque. The Stage II was even wilder and not recommended for street use. Car Life managed 0-60 mph in 6.1 seconds.

Buick GS’s went even faster in 1970, with the introduction of the 455-cid, 340-hp V-8. A Stage I GS 455 was timed by Motor Trend at 13.79 seconds though the quarter mile at 104.5 mph. The big news for 1970 was the conservatively rated 350-hp, 455 GSX. The car was a wild package in yellow or white with black stripes, and it carried standard most of the optional equipment from a GS 455, including hood tach, spoilers, sway bars, four-speed, Posi, and a heavy-duty suspension. Only 678 were sold; 491 in yellow, and 187 in white.

The GSX package was available in 1971 and 1972, though power gradually fell, due to emissions. The package was available in any color and with several power plants up to the 345-hp Stage I. Only 124 were sold in 1971 and 44 in 1972, so a real one is a rare find indeed, and verifiable provenance is a must.

The 1972 GS and GS 455 would be the last of Buick’s muscle car line until the Grand National ten years later. While no single year of this generation of Buick GS sold particularly well in their day, they are now remembered as one of GM’s premier muscle cars. Stage I and Stage II GSs in particular combine copious amount of torque and abundant power with luxury.