Decode this P case? Anybody?

Should be a code stamped on the other side which will give you info on application (full-size or Corvette), gear ratio and assembly date. If that is missing there should be dates on the posi unit and the ring gear as well as the tooth count. Example 37 10 3:70 ratio


Well Known Member
Supporting Member 9
That is a Richmond Gear. Nothing there indicates tooth count. You will have to count them. I think the ring gear looks thick like possibly a thick 4.11 or 4.56 on a series 3 carrier.
Last edited:


Well Known Member
Supporting Member 2
Tom Parsons is thinking the stamping for a 1964 x frame was on the front of the right rear axle tube, not on the bolt flange like in 63 and earlier.