The BC guys have amazing terrain right out their back door and probably don't have the traffic that now exists in CO which makes getting out so much harder these days.

CDL - Center locking diff. One of the better upgrades to the d2s, really get the most out of the traction control and my understanding is that all D2 LT230s are interchangeable. ALl LT230s are mechanically interchangeable but some have different sensor ports or lack them (older defender and probably early d1 units). Oh don't get a 03 TC if you are in any way interested in keeping your CDL (as you have an 04 and should have one from factory). The 03 units did not have the capability to lock the T-case...

 

@austinlandroverbill driveline whine comes from a couple of places diffs and transfer case are the most common. A good quality gear oil helps I use Amsoil 75/140 and have no noticeable whine.

And we have to know to work on our trucks up here ,too many shops will not touch them, besides it is a good stress reliever to work on your truck, the cursing really helps.