Water proofing
Ditto on the door seals on my '93. I've only been in water up to the rubber side rub molding, but that's about 10" above the door sill.... nary a drop inside! As for the diff breather tubes: definately extend them up as high as possible. The front one on my truck is just below the hood level on the firewall, and the back is above the fuel fill door. I was able to wire tie it ti the fuel filler vent tube, and remember to leave enough slack to accomodate max diff travel both upm and down, as Chad N points out. Another tip I saw in an OR mag, and have done. is to install a cheap see thru fuel filter near the upper end of the breather tubes (You know, the plastic ones that you often see on V-Dubs, and only cost about a buck). This helps keep not only water but also dirt out of the diff. As the diffs cool rapidly when you hit water, the air contraction can suck a lot of junk back into the diff, and the filter helps block that. The see thru lets you judge when to change the filters,