well, a dead alternator is a lot less costly than a hydrolocked engine. and your truck will still continue to run (for a short time) with a dead alternator... suck down water, you'll know it right away.

short answer is, its really tough to completely waterproof a gas engine to run totally submerged underwater. diesel engines are better suited for this. words of wisdom... don't buy a snorkle because you think it will protect everything under your hood from the water, you'll be sorely upset with the outcome.

-Rob