What was the minimum? Something around 1900 or 2000 production cars?They were made for the sole purpose so they could raced in NASCAR. One of the rules was, the car had to be a production model available to the general public, and they had to make so many to be legal for use in NASCAR.
Ford did the same thing in 1969 and 1970 with the Boss 429 engines, offered in the Mustang, so they could sue that engine in NASCAR.