L78, According to this website
http://WWW.Chevelles.com/radiotech/database.html The date is in the model number, but it is only the year. For example if the model # is 91BFM2 this means it is a 9=1969, 1=chevrolet, B=B body or full size car, FM= AM/FM stereo pushbutton with hidden MPX, 2=Second design run. My radio has an aditional sticker with a date of 5/14/9 that the website has no information on. Thank for the help guys.