Before you get too involved, consider the other mods needed. Don't forget to waterproof your Dizzy-Cap, extend ALL vent tubes (axles, engines PVC on valve cover if you have 1, Trans breather, make sure all lights a waterproof lest you blow hot bulbs....and anything else you can see)
I'm sure I left a few things out. Maybe I'm being over cautious, but others will likely (hopefully) chime in. Also consider that each deep sea excursion will require a good hour w/a pressure washer getting all the sand/mud/fish out of every nook & cranny. Making sure all your electrical wiring isn't corroding at a very rapid pace, by the water crossing and the pressure needed to clean it . Maybe a dedicated leaf blower to dry it out too?
And I'm sure you know that you don't want everything all hot when you go deep. That means no long descents, heating the brakes, before you hit cool water & warp rotors. Also make sure any welds in the hot exhaust are up to rapid cooling.
Also plan on greasing EVERYTHING w/a zerk & adding a few more! This post by J-Hammer is a good read before you embark also. http://www.jeepforum.com/forum/f8/wa...5/#post6395695
I don't mean to discourage you by any means. I actually salute anybody taking on such a project, and please post some pics of what all is involved in your endeavor.
Good luck & keep us up to date!