Originally Posted by ole85
wanting to buy the pinion and gears or a kit if there is a such thing for a 4.10 diff i don't want to change over just in case i hate the set up
The issue is not getting the gears, its finding someone who is willing to install them properly. The M diffy in the E9X M3 is a little finicky when it comes to tolerances in the diff.
Here's diffsonline.com page that has the ring and pinion.
You can buy a re-manufactured diff from bimmerworld.com. Here is the webpage..