If I was going to buy one to install, I'd be looking for one made by
Tractech .
The Truetrac is an all geared limited slip, smooth, tuff, and no clutches. Used in many medium duty applications. Or you could go straight to the Detroit Locker. A little harsher action, but positive locking, and tuff as well.
If I didn't have a L/S from the factory, I'd have one of these.
I don't know what's available, and my 'puter locked up when I went to the heavy duty application list.