Looking at buying this g-box but don't know what it is exactly and neither does the seller. He says it was off a running 1275. I want it to put on my 1098 from a Morris 1100, which has a 4ish :1 ratio from the morris, too low for the mini. Really, I just need the diff. Any way to tell what it is or if it will work? Will the diff just bolt into mine?

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1972 Mk3 Mini 1000, 1150cc supercharged.
https://www.ausmini.com/forums/viewtopic.php?f=3&t=95872

A 22G68 casting with a remote gearchange is typically used on Cooper models, both 997 & 998. The laygear part number would give more clues.
It would have started life with a diff ratio of 3.76:1, 3 speed synchro.
I'm no expert, but the casing doesn't appear to have the tiny notch cut out of the front left side for a 1275 crank clearance?

22G68 was also used on the 850 and Deluxe. However it could all have been changed in the last 50+ years.

To swap the diff you need the crownwheel and pinion gear. You might find the bearings and diff pin need replacing once you're in there.

You can count the number of teeth on the crownwheel and pinion and work out the diff ratio

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Cheers! I have been given only two numbers to work with 22G68 and 5/25180
With 12" wheels and standard size tyres (165/60) which are 1.5" or so higher than 10" tyres, maybe the 3.76 if it is that will be ok? I was thinking of like a 3.2:1 or something because I don't want it revving too hard on the highway.

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1972 Mk3 Mini 1000, 1150cc supercharged.
https://www.ausmini.com/forums/viewtopic.php?f=3&t=95872

I reckon the 5/25180 is from a Deluxe

My car has 3.76 diff and 165/70R10 tyres - at 100kph it's approximately 4100rpm, which while loud is fine for a mini engine.
3.44 out of a Cooper S or clubman is a good compromise between acceleration and cruising. But any gear ratio could be in that gearbox as it's possible someone has changed it in the past

12" and 10" tyres are also essentially the same rolling diameter:
165/70R10 = 485mm diameter
165/60R12 = 503mm diameter
Difference +3%

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Is there any way of telling the ratio without pulling it apart?

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1972 Mk3 Mini 1000, 1150cc supercharged.
https://www.ausmini.com/forums/viewtopic.php?f=3&t=95872

Yes, count the teeth on the crownwheel and pinion as mentioned above. It's also possible you can find the stamped part numbers on the crownwheel

3.44 diff is 62/18 = 3.44 . You can mark the first one with whiteout or similar to count from.

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You can mark the crown wheel too with a marker pen, you can see it from above if you look back.
If pinion is 17T it could be either a 3.76 or 3.64 diff.
If 18T its definitely a 3.44.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Being a remote g/box with those couplings could it be a Mini K gearbox?

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67 Deluxe
Dry suspension
1293cc, 11:1 comp, RE 282 camshaft, 45 Weber, extractors etc
4 synchro close ratio gbox
Cooper S brakes, no booster
Stealth box, as Doc says "goes harder and idles!"
RH tank cos I needed it crossing the Nullarbor etc..

No, Mini K had a 22G1128 box, 4 synchro.
Your box is 3 synchro, probably a deluxe.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Check part number stamped between 3rd & top on cluster gear.
22G204 = Cooper 22G76 = Cooper 22G1100 = Cooper S Mk
22G232 = Cooper S Mk1 22G231 = B Form gears 3 Spd Sync
In my opinion this is a "B"Form gear box,
'

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" A Hundred Years From Now It will not Matter what my Bank Acount Was,
The Sort Of House I Lived in, Or The Kind Of Car I drove ... But The World May Be A Better Place
Because I was Once Important In The Life Of A Child"

it *looks* like the front of the casing has been ground to give clearance for the 1275 crank, but not having done one myself I don't know...

normally if you put a 1275 on that casing the crank will hit it

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did I tell you that I won a trophy?

These have been ground out for a 1275 crank.



They went a bit too hard on this one

What are you intending to put it in ? You can get later leyland complete boxes with better ratios for not big bucks .