Your truck most likely came with 3.55 rear and 3.54 front. Most people with 35" tires who change gears go with either 4.10 or 4.56. (it seems to me that the majority lean a little more toward 4.56) There is quite a bit of information available on the subject. I can't post a link to anything at the moment since I'm on a public computer right now, and I don't have access to all my saved links. But if you search a little you will find what your looking for.
One thing to keep in mind, is that you will need to re-gear both the front and back in order to continue safely using 4x4. (not trying to insult your inteligence if you already know that, some people don't) Also, your Dana 44 front diff will require a new carrier with the 4.10 or lower (higher number) gears.