The actual production was:
392 Charger 500
505 Daytonas
1971 Superbirds
The requirements for Nascar on 69 was for a 500 units built.
They took the last of the Charger 500 and had them converted to Daytonas, so they didn't have to pay for the difference to be made for the Daytonas, since the Charger 500 was the base for the Daytona.
(We're talking the one year only 69 Charger 500, not the trim package Charger 500 available in later years. True Charger 500's had the back window to be flush with the back of the back pillars, not recessed like all other production Chargers which was send out and done after the factory)
Chrysler played "hide-the-coconut" with Nascar officials. They had the Charger 500's parked in a few different lots. While they were counting cars in one lot, they would move them to another lot to be counted again. Some cars were counted twice to fudge for the difference in the Nascar requirement and how many they had actually shipped/sold.
In 1970 Nascar changed the requirements to one per dealer. There were 1,921 dealers in the US, and 50 dealers in Canada for a total production of 1,971 Superbirds.