Hi
I have a type1 IRS dogbox. (no synchro) so pretty hardcore to drive tho...
It's build in the 80's for my F33. It s was an expensive an UNUSED gearbox. Untill now still not. (I bought the car and I'm going 930 gearbox)
If youre not in a hurry, I will open it to check the gear-ratios. But I know they are long, beacause that car had to drive 150mph!
Open diff.
If youre interested, let me know and I will check everthing and take a lot of pictures for you.