timbo Interesting info, thanks.
What I want to do is cut the axle tubes off of the 140 diff, then get them welded onto the M78 or 8.8 diff so I don't have to stuff around with rear brakes and handbrakes, etc. - I can use ordinary Volvo rotors and calipers, etc and not have to worry.
M78 Borg Warner diffs are very hard to find these days too.
AFAIK, 4.1 gears are as short as they get for the M78 (ex-Pintara - about the only time a Pintara is useful for anything)
Are 4.27 gears available for the M78?
The 8.8 does have a 4.27 crownwheel and pinion set available.