This is in my 1969 Cutlass S ...
I cannot find any codes on the right axle, or the left for that mater.
I hoping not to have to remove the cover to find out.
If it is original it could be Type "O" ? (67-69).
It is an Open single track now
I'm just confirming what it is prior to replacing it with a posi unit - though not sure what route to go yet

Thx

 

Yes it's a Type O.

 

Thank You

 

Look on the front of the tube, close to the tail pipe.

 

This is my Right Axle facing front toward the top - I see nothing - and I have checked like 3 times after cleaning it up +- There is a vent hole on top (without the rubber plug sealing the hole +-)

 

Yeah, I see that. Sometimes the stamp is so faint that it is invisible. Try wetting it with WD40.

 

ALL ARE ON THE PASSENGER TUBE FACING THE REAR OF THE CAR AND THE LETTERS ARE USUALLY UPSIDE DOWN
2 LETTER/ NUMBER CODE
Geez, Not yelling with the caps. . sorry.
IE - R2 SA SC something like that
\Looks like it might be a bit tight where you need to look behind that passenger exhaust tube.
wire wheel / flat file / if it is too rusty it may be a moot point.