My rear end has this number on the fwd pass side axle CB 012?B. other side is GM53 and casting number 3917123NF and A14 9.
Can anyone tell me what this is and the ratio? Thanks much
Howie

 

3.36 NON POSI rear chevy 10 bolt

 

Cast January 14th,1969. Although the finish date should be after the casting date,so not sure if all those numbers are right.

 

via photos I took of the rear end. Numbers are correct except the is an X over the casting number and an O over the date. I got the car partially started and am finding things don't match up,
thx, Howie

 

3.36 chevy 10 bolt is my best assumption also. Trouble now is figuring what speedo gear to use, I'm guessing a 42 or 43. ANY HELP???
26" tires, 18 tooth output shaft speedo gear?
Thx, Howie

 

Start a NEW thread with trans speedo gear which one. You will get a better turn out of answers that is a trans question. Jim

 

I ended up having to call a tranny specialist. He said with 26" tires I'd need a 46 tooth gear which is not possible. He said I'd be 1.5 mph high at 50 so I will use bigger tires and that will fix that. Thx, Howie