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

C ompared to more well-known vehicles, like the Chevrolet Chevelle, the Dodge Challenger, and the Plymouth 'Cuda, Buick's GSX ...

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.