If you absolutely have to have a snorkel, I would want to be sure other components are able to tolerate full submersion in mucky water.
The computer (I'm not starting that argument, so I'll stick with the word computer...), hangs pretty low for one thing.
Can it and other stuff hold up to water submersion and potential corrosion after? The front diff, transfer case? All water tight?
Not telling you it is a crappy idea.
Just wanted to relay some things to consider if you go that route...
When I had my Jeep TJ, I heard stories of Jeep owners putting snorkels on. Mainly because they looked bad-ass driving around town. Then the horror stories of when they actually forded deep water and found out quick, that their snorkel system was not actually water tight. They sucked in water and had to deal with that mess.
If you get a snorkel. Whatever you get, you are going to want to make sure there is no doubt that it is 100% water tight, if you plan on fording water up to your hood. Even if it is plastered with RTV on every joint and pinhole, heat flexing and road vibration can make almost any attempt to seal out water fail. With air intake, even the smallest leak can be a huge problem quick.
One other thought... Better make sure door seals can hold back the flood waters too. Things like airbag modules and other electronic components GM placed on (or near) the floor probably don't like getting wet either.
I had a Jeep. I like adventure as much as anyone. But, If I were swimming through water deep enough to require a snorkel... I don't think it would be my stock Tahoe to do it in. I would probably look for something purpose-built for extreme off-road action with a not-legal-for road-use super high suspension lift and 35"+ tires.
Again, not dumping on your idea. Just want to make sure we don't see posts about how to deal with a hydro-locked engine or electronic issues later on.
Post pics of the project. We would all be interested in seeing what is done.