I'm thinking about taking my LBZ in for it's frist service. It has 1,400 miles on it. Is that sufficient for complete break in? I'm thinking of having the oil, transmission fluid, differential oil and all the filters changed (not air). Any reason I shouldn't?

IMO the oil for sure and the tranny filter, but I would wait at least until 2K for the diffs IIRC they take a little longer to break in.

i would not bother the differential except to top it off with synthetic. jmo