Detroit locker

Eaton has nothing to do with that piece. That is a Detroit Automotive Products company (DAPCO) locker, known as a Detroit locker..
Their logo follows the 81310 number.
If it's not broken inside, it's the strongest lsd you can get. Also, the noisier (around corners).
Just to clear this up, it AIN'T a limited slip differential. It's a locker. It has 2 positions. Locked or unlocked and nothing in between.