I have a 1983 camaro berlinetta i removed the top dash panel and in between the windshield and firewall on the passenger side i saw this molded into the dash 82-JFMAMJJASOND,and under that it is 83-JFM..its not a sticker or metal tag its molded into the dash itself..is it a build code or something like that,and for what year 82 or 83...thank you