Those older 8-3/4 have the ratio stamped on the bottom. If it is a Sure Grip, an "S" is also stamped. I can't find anything about this anywhere. I should have taken a few pictures of the example that I had. I'm thinking it was a rear out of a '62 Savoy with a 741 case 3.23 Sure Grip so they were stamping them at least until '62.