Why are looking at replacing the diff? Gear change? Worn out? Damaged?

If you might have any use for a locker, it is well worth it to do it now, as you will have to pay the same for the setup. As Rob mentioned, these units are almost 20 years old and most likely they do not function very well. Rebuilding them is probably going to cost as much as a locker.

Just something to think about.

Michael