The ofna diff cups use the 8mm ball end for the bones and will work with your center bones
The distance between bearings is 29mm, but the bearing seat is not bumped out like yours so that’s probably the difference.
The main measurement are:
End of cup to cup – 78.75mm
Center of cup to cup –...
Aah it’s got a spool for the center diff.
I would look at the Ofna LX 2 center diff, they use a 51T spur and hold up well. You can get them on the bay for $20.00 shipped with the brakes included.
14T bell and 60T spur = 4.28:1 ratio
12T bell and 51T spur = 4.25:1 ratio, that would put you...