I just pulled the cover off the rearend in my 1966 el camino. I know that this is not the rearend that came in this car. I discovered that it has an Auburn posi carrier and a Richmond 4.11 ring and pinion. I don't know which 10 bolt this is as they made many diff 10 bolt rears. I took this number off: 9779822.
Any help is much appreciated.