I believe this looks like a chev 12 bolt but I was unable to find the codes on the axle tube on any chart or list (RC 08 8k or R) the rear end is in 68 cutlass s 3:08 ratio /4speed car ,does not look like it has ever been out of the car to me ? any help in ID and code meaning would be appreciated .

 

RC = 3.07 open chevy 12 bolt used in CANADA built '68 Olds A-bodies

 

It would help if you would go into your user CP and post where you are located.