reviving the semi-dead i have a 350+ hp one wheeled wonder. my s4 t2 diff is dead when i did the math i calculater like 500 bucks to rebuild it using the parts from mazdatrix. am i reading this wrong? just looking at cost per disc.....

you can buy my lsd
now accepting foodstamps and/or illegal drugs!

how much is an s4 diff rebuild kit?

which version is this?
 

Torsen?I bought this but got a KAZZ instead.

Just for your information i have run into 2 different lenghts of TII output shafts (both from open TII diff) and 2 different lenghts of TII halfshafts (again, both from open TII diff).

I am not positive if is S5 vs S4 difference, or US vs EU difference. It is interchangeable, but you always have to keep right pairs together to maintain proper final lenght, or you will be pulling output shafts out of the diff (it happened us when we mixed it).

Proper setup is obvious :

longer outputshaft + shorter halfshaft
or
shorter outputshaft + longer halfshaft

It is possible to fit longer outputshaft+longer halfshaft, but its very tight. I would not suggest to run this setup on track or any kind of stressfull driving.
As mentioned already, its possible to fit shorter outputshaft + shorter halfshaft, and result will be pulling your outputshaft from diff when you put some stress/cornering/drifting on ther suspension - not good - and you will notice it.

bump
any one know if this is T II or not?

It is a Torsen diff.

As far as if it is a Turbo or non turbo diff, you would need to measure the ring and see.

7" = Miata/ Non turbo FC
8" = Turbo FC/FD/929 MPV etc