Jim is right. Durability of the gears is a huge concern. I've had a bit of a problem keeping pinion gear teeth on the pinion gear.

Where did they go?
ForumRunner_20160103_182322.png

Oh, there they are.
ForumRunner_20160103_182302.png

This was my 2nd differential, WITH a Wavetrac LSD. My original diff died when one of the spider gears blew up.

For diff #3 Unitrax hardened and finished a new gear set for me. Wavetrac was awesome and rebuilt/upgraded the LSD for a reasonable price even though it was not the LSD that failed.