This 4.10 torsen came out of my '96M parts car. As you can see in the picture, one of the carrier ears is broke, but I obtained a new carrier for it. I have a drive shaft for it, but do NOT have good axles. This should be an easy swap to upgrade any '94-05 Miata with an open diff, or it will go into a 90-93 Miata if you pick up some axles.
$350.
Attachment 4642