1977 Chevrolet K20 6.6L V8 VIN: R CARB Naturally Aspirated GAS. 1977 Chevrolet K20 5.0L V8 VIN: U CARB Naturally Aspirated GAS. 1976 Chevrolet K20 6.6L V8 VIN: U CARB Naturally Aspirated GAS. 1976-1977 Chevrolet K20 7.4L V8 VIN: S CARB Naturally Aspirated GAS.
