In pulling power booster and brake master I see they are dated 265 & 268 day of year ?. With a 5468309 side number & EA on end of master. How do I tell if its 68 or 69? Could this be orignal booster and master for a 1969 camaro with engine build dates last weeks November and car build second week of December? As I'm going through car I keep finding quite a few parts that seem to be orignal. Starter, Radio, Trans, Rearend, Distributor,