What option on a 1966 Plymouth Barracuda S code is there a number in the vin that indicates a S code car?

The "S" code in the VIN of a 1966 Plymouth Barracuda indicates that the car is equipped with the high-performance 273 cubic inch V8 engine. Specifically, the VIN will start with "BH" for Barracuda models, and the fifth character will be an "S" if it is an S code car. This designation helps differentiate it from standard models that had different engine options.