Hey BB-Dave,
I checked the rear end again today and verified that it does appear to be a 3.91 Sure Grip. I've checked my 1969-1974 Mopar Broadcast Sheet Decoder Manual which lists the 3.91 as code D57 on the sheet. On the option code listing I have for 1969 it says "A31 69-71 High Performance Axle Package w/ 3.91" I took a picture of the numbers on the side and you'll see it reads 2070741 with 26 below it. There is also some even smaller numbers which I'm not sure if it was 222 or if there was a number or two after it. You can also see in the picture what appears to be a orange paint factory marking. I was unable to find a ratio tag on any of the bolts, especially the top where what I've read is normally there. Pics attached.
Thanks again,
Dan
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