I'm not quite sure what you're asking - I assume domestic differential means something from the US of A and that this is for the trike project...

...all I can say is that most OM617a's had the 3.07 rear end ratio on a tyre / wheel combination of 195/70 R14

The differential was changed to 2.88 in the last years of production of the W123

You kind of need to consider your ideal sized wheel / tyre combination to work out what how fast you want to drive towards sharp bends on three wheels!

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!