1970 Chevrolet Chevelle SS 454 LS6 Convertible
General Motors lifted its displacement ceiling on intermediate cars for 1970, allowing Chevrolet to offer the 454 CI big-block in the Chevelle for the first time.
The LS6 convertible represents the absolute apex of this brief performance window, combining maximum horsepower with open-air motoring in extraordinarily limited numbers. Estimates suggest that only around a dozen LS6 convertibles were built from the total 4,475 LS6 engines produced.
The cowl induction hood featured a vacuum-operated rear-facing door that channeled high-pressure air from the windshield base directly to the carburetor.
Black Rally stripes and SS badging distinguished the Z15 package, while power-operated convertible tops added nearly 200 pounds over coupe variants. Five-spoke SS wheels and wide-oval tires completed the aggressive stance.
Under the hood sat a 454 CI Turbo-Jet V8. Output reached 450 horsepower at 5,600 rpm and 500 lb-ft of torque at 3,600 rpm. The close-ratio Muncie M22 four-speed or Turbo Hydra-Matic TH400 automatic transferred power through 12-bolt rear axles with ratios up to 4.33:1.
Motor Trend recorded quarter-mile times of 13.8 seconds, making the LS6 the fastest intermediate of 1970.
Source
