The G80 GovLock differential is the basic limited slip option from GM. It locks when there is significant difference in RPM from one wheel to the other (one is slipping). The problem is that if you spin it up too quickly (burnout or stuck in snow, etc.) the engagement of the locking mechanism can break parts internally during a sudden engagement. Due to that issue, some performance guys nicknamed it the GovBomb differential.
There are several YouTube videos for the GovLock, so maybe one will be helpful for you.
Bruce