Those are Casting Numbers & Dates. They wont tell you the gear ratio.
It looks like a 9" inch Ford to me.
For ratio Info, you'll have to count the Pinion & Ring gear teeth & divide Ring by Pinion teeth #.
Can also rotate the tires 1 revolution & count the Driveshaft revolutions if Posi Diff. If Open Diff rotate 1 tire 2 revolutions & count DS revs.
Tag codes >> Ford Rear Axle Assembly Identification - Page 01 - FORDification.com
Other IDs >> http://www.maliburacing.com/ford_9_i..._nine_inch.htm