I have a 1965 chevelle ss and cant find the casting number on the rearend. I looked on the side facing the rear and the bottom of the tubing structures. Any other places to look? It is the original rear end.

According to Cheverolet by the Numbers, the axle code is located on the forward-facing part of the passenger side (or left) axle tube. It should be a 7-digit code and reads left to right.

Thanks i found it

I have a 1965 chevelle ss and cant find the casting number on the rearend. I looked on the side facing the rear and the bottom of the tubing structures. Any other places to look? It is the original rear end.

The assembly date and code would be stamped on the axle tube as indicated by Bart42, but the casting number would be on the bottom front of the center section. A 65 10 bolt would be casting number 3959139 and a 65 12 bolt would be 3859140.
Bruce