post 85 is mine -
http://expeditionportal.com/forum/showthread.php?t=2299&page=9
I think it is water worthy, but not sure if having a supercharger will make things any worse
I had water go over the hood only briefly (couple seconds) maybe 3-5 times and only due to driving a little faster than I should have and breaking thru the bow wave. As you probably know you have to try to drive at such speed as to create a wave in front of your truck, so that water level in front of the truck is higher and at the engine bay it is lower.
Overall never had problems with electricals yet, except for the starter positive cable connection point getting rusty - just had to take off the positive cable from the starter and clean the area to make it work again (also put some dielectric grease ont here to help protect it from rusting again). I am pretty sure that majority if not all electrical connectors onthe outside of the cabin are made water splash proof from the factory to resist heavy raining and car washes, but something like a fuse box might need a better seal. I have also heard of people trying to protect their ECU's by placing them somewhere higher up in the truck (perhaps siliconing connections could work too).
I have also extended all the breathers from differentials, tranny, and transfer case into the airbox.
Anything greasable will need extra grease due to washout by water, I imagine.
Also, check your steering rack and CV boots before water excursions to make sure they are not ripped, or you are risking getting water/mud/sand inside and destroying the inne tie rod ends and/or CV joints.
Overall I think people kinda exxagerate conductivity of the water, as far as truck electrical system goes. I wash my engine comaprtment with water and it gets on battery positive and negative terminals too and nothing have shortened out. so far

now sea water, with lots of salt in it, will be worse, but you don't want to drive much thru sea water anyway as it is a rust ticket, unless you wash your truck right after it veryb well
driving thru deep water sure is fun though!

just do your homework first...