Well, what you have to remember is that if water gets up that high above your engine, you're pretty screwed anyway, cause it'll probably be in your distributor, inside your wires, etc, not to mention your fan blades will probably have pulled themselves into your radiator. You more than likely won't be "sumberging" your engine, you just need to plug all the major holes (i filled in preheater hose inlet and egr stuff with aa bunch of silicone). It's just to keep most of the water out. Heck the seal is done with duct tape, how waterproof do you think that is? You really just want to keep the main intake from sucking up a bunch of water. Don't sweat the details. At one point, I had water up to the door handles, and about a foot of water inside the truck, but it still kept going, and i didn't get any water in the diffs, engine, engine oil, or tranny. The setup I had worked out just fine.