Good question, Doc. I had one on my old transmission which is now on the shelf because my new Rancho Pro Street has the super diff with the HD cover and won't fit. I'm not sure I really need one though, 'cause I don't drive it that hard and I kind of like the stance without it. I may donate it to a contributing member for the cost of shipping or put it in the raffle if I can get it to Carlisle.
It's lightly used and in very good shape. I think it's a CB type with the straps that pull down on the axles.