Does anyone know if the splined axel flanges from a late model W126 (the things that stay in the diff that the CV bolts to), will work in a W123 diff?

I want to put a 3.69 ratio in a late model SD and I have a 240D diff. I have read that the large and small housings are the same width at the flanges, but have not confirmed personally.

I know I would have to fab up an adaptor to mount the pig, and I am hoping that I can pull the flanges out of the SD pig and put them in the 240D one so I wont have to mess with the axles.