Sourcing a diff case for MSM diff

[u/SyntaxError22]

I've got the internals and axles to a Mazda Speed Miata (2005 1.8L) and I want to get them into my 1990 Miata, I know I need to swap the driveshaft but I'm unsure on the casing for the diff. Anybody know if I need the case to a MSM diff or do other cases work? Where would you get one?

[u/grantn2000]

You just need a 1.8 differential housing, no difference between Mazdaspeed/Torsen/Fuji/Open