Does it matter which one I use? I'm not asking about the gear. I have a choice of several.
From the photo, both of these housings look like they survived some sort of crash/crunch event. Perhaps I'm overly cautious, but I would very closely inspect either, especially dial indicating for surface and runout issues?
Either one will work equally well.
6 one way, half a dozen the other. I had bolts when doing mine so I used bolts.
Some have bolts some have studs, depends on what year it was made.
The boards that the carrier halves are sitting on, is the rounded area for holding the differential housing?
According to the encyclopedia, studs were used through 1920; 1921-1927 used bolts. Bolts eliminated one part of the two--the nut. Henry always economizing.
Dennis Brown: Yes, it is. Made from 2x6 scraps for the perfect price.
The studs were used on the earlier models. Just be sure to use safety wire on them, and not cotter pins!