Yesterday I was working on the rear axle on my 69 camaro. And got these numbers off of the housing and axle. On the front of the pass. side axle were stamped C BP 1017 G1. The best I can figure out is that it is a 2.73 ratio, 10 bolt non posi, Oct. 17, Detroit Gear 1st shift. What does the C stand for? My casting # is J89, foundry control # is CON1, test marks of 67890 and 12345. What do those numbers mean? Thanks.