This 1970 Chevelle spent 35 years parked in the Dallas area, and what’s underneath the dust is about as good as barn finds get — a factory Tuxedo Black LS6 454 rated at 450 horsepower, backed by the desirable M22 ‘Rock Crusher’ four-speed. It’s exactly the combination Chevelle collectors call a holy grail. Watch to see what three and a half decades of dormancy did to one of the rarest muscle cars GM ever built.