Hi guys. I've been loaned a 1275 motor and gearbox to get my Mini back mobile after a crank meltdown in my old (but really new- long story!) motor.
It's a 12H902UH prefix motor on a gearbox casing number DAM2886.
Allegedly, since it came with the rest of the car, it's from a 1977 Moke Californian, also allegedly with only 53,000 odd km on the clock.
The lender is pretty sure it has a 3.444 diff in it, but I find that a bit hard to swallow given the 12 (or 13) inch wheels on a late Moke. I don't intend changing my Deluxe from the 10" ones.
If it has that diff, then I'll try it as a unit, otherwise I need to swap gearboxes, which I'd rather avoid if possible. Equally, if what I've read on the odd pommy forum is accurate then it may well be an early A+ box which would perhaps mean all sorts of mismatches with drop gears and idler bearings I believe.
Is anyone out there able to enlighten me please as to the likely diff ratio without me resorting to stripping the thing? Needless to say, the sticker showing the ratio, that occasionally survives on diff housings, is long gone.
I await input with a mixture of hope and trepidation!

Cheers, Pottsy
With The info you gleamed from the below, and With a DAM2886. gearbox case number,
you can be sure it will be the large idler gear model.
if what I've read on the odd pommy forum is accurate then it may well be an early A+ box which would perhaps mean all sorts of mismatches with drop gears and idler bearings