Hello.

The scheduled production date of your car would have been either 21G or 24G, but my money would be on 24G, which is August 24th of 64. The D.S.O. is lost forever, unless you get lucky and find an original build sheet or window sticker in the car somewhere. Your rear axle had a tag on it when it left the factory, which has the axle ratio on it. It also has a date code, so you can see if it's still the original rear end, but, the D code cars all came with an 8 inch rear end with a 3.00:1 axle ratio, which would be 1 on the door tag. The transmission also had a tag on it. If that's still there it would tell you what you need to know.
