66 vs 67 A Body bucket seats.

To my understanding, headrests were mandatory by law January 1st 1968. You just got believe auto manufacturers knew it was coming much earlier than that, like in 1966 already.
You guys are right it was 1968, the last day!
12-31-1968


Do a web search
https://teacherscollegesj.org/are-headrests-in-cars-mandatory/

875D87E7-74C6-4330-B3CF-D00C9A85F924.jpeg