I had a Gov-Lock on a 12 bolt 1/2T 4x4 with 33" tires. Exploded the diff going around a corner, not getting after it.
Then I installed an Eaton Posi
http://www.eaton.com/Eaton/ProductsS...posi/index.htm
I blew the spiders out of it 4x, but couldn't afford to put in a Detroit Locker. Sold the truck.
Bought a 1970 K2500 GMC. Rear diff was blown out when we bought it. It has a Detroit locker and 4.11 gears. Not gonna have to do it all again.