851 Axle Ratio Stamping

That would be March 1935. It would be a late style diff. few parts interchange between early and late Most early style are 51-10's (sept 34 to feb 35)
There are at least four different ratios. Some had three gear planitaries .
Frank in Ohio has forgot more that I know on this subject.

Also, how much does the high range reduce the ratio? Is it a standard amount common to all the cars?

I see a lot of numbers, but which one is relevant? Also, which photo is the early -- the top one? My car's differential is like the one at top. There is a casted-in number that appears to be E333.56. Above that is an upside-down stamping that appears to be 3x35.

The picture shows the early and late style two speed rear differrentials. Few parts parts interchange. The early style was phased out in Feburary of 1935.
The picture . The info you request is stamped into the housing. The sixes and eights are the same EXCEPT for the size of the axel shafts.

Where on the differential is the stamping that shows the pinion and ring gear tooth count? Also, what rear end ratios were available in 851s, both super-charged and non-super-charged? Thanks.