Rare, unrestored, and sporting a numbers-matching drivetrain, this 1970 Buick GSX Stage 1 is a time capsule worth six figures ...

Produced for just three years (from 1970 to 1972), the Buick GSX started its life as a performance package atop the Gran Sport, which turned into a car derived from the Skylark platform.

Replacing the Skylark's 300ci V-8 with a 325-horsepower ... so their car was substantially faster. The 1970 Buick GSX was the most kick-ass GM muscle car of the classic era, and it could literally ...