suck in dust and if the water is up to your carb (I'm not EFI) you're already stuck
the snorkel pulls in air from above ur truck, where its cleaner, almost no road debree from other vehicles. i live in west texas and go through an air filter every 2000 miles drivin on the road and i dont have a snorkel. a friend of mine does on his chevy pickup and goes about 18,000 miles before he has to get a new one, and he's got a snorkel.
the main things to worry about water proofing are ur computer, distributor, spark plugs, and ur air intake(engine wise). friend of mine uses an oil ring on his distributor, has no problem crossing water up over his hood. used electrical tape around his spark plug boots just to be careful, guess it helps. no computer for him, carb.
