Maddog,
You have a new PM so check it!
Warmonger,
The reason for the 3.75" backspacing was simply because that is what AC reccomended with the revolvers. If you look on there site it tells ya.
Yes I might only gain a 1/2 inch at the low point for around $320 being the cost of the body lift and revolvers, but I will also gain a large amount of flex in the rear. More wheel well room meaning I can run the front disconnected, and a taller stance.
wqbang,
Lockers, and T-Case gears void the hell out of your warrenty! I only have 14k on my X and I have the extended 100k warrenty. Currently the Nissan dealership in SA has no problem with the lift added and larger tires and said it wont cause warrenty issues. I had them clear it all before I installed everything.