Whether 3:55 gears are for you depends on how you plan to use your truck. If you plan on going on long drives, or drive at highway speeds, then go for it.
I put these beauties in my truck, and its one of the best upgrades I have ever done. I have installed several sets of these in my and my buddies truck.
If you check out my Webshots page, there is an album dedicated to this swap.