explain center locking Diff.

[M1911]

Do you have a V8 or the V6? Why would you need 4-lo?

I've got the V8. I don't "need" to use 4-lo. I've run it in 4-hi and 4-lo. But I can make the same speed in 4-lo as 4-hi with less throttle input, and it seems that the engine isn't working as hard.

Try it both ways and see which seems work best for you.