Interesting discussion. My 1968 elkie SS (factory L78/M22) has a KO coded rearend (4:88 posi) that is dated just prior to the car's build date. The rear was not on the Canadian docs (only shows G80 - posi), so do you figure that rear was installed by the dealer or was it just coincidence that someone swapped the rear for a correct dated 4:88 at some point?
