I traded the original owner for that car, I didn't buy it new. He had been a dealership mechanic but he was a flake also, he insisted that the rear end was the original one that came in the car, he had no reason to lie about that
I didn't say it had any I.D. numbers on it, only that it was a 741 case with a clutch type posi and 3.91 gears in it
I'm not exactly sure when Mopar started installing the 489 cases and the other Eaton type posi, I know it was sometime in the 1969 production year