I am currently running a set of 305-70-17 Nitto Terra Grapplers on my 2006 CTD. Falling only second to a set of Maxxis Buckshot Mudders, they are the worst tires I have ever owned. I have 7,000 miles on them, and they will not stay balanced. I've taken them to multiple garages, and one that has a road force balancing machine. Each time when they balanced them, they rode smooth for a few days and then back to bouncing again. My truck has a 2-inch leveling kit on it, it was already installed when I bought the truck. I love the way a 4x4 looks when it's leveled. I am interested in getting rid of these Nittos and getting something else. My question is, what tire size can I run on the factory 17 inch rims without the truck looking like a roller skate with the leveling kit, and secondly whats a smooth riding E rated tire? I had Toyo MT's on my 2004 and they rode as smooth as silk compared to these Nittos, but they don't come cheap. Have considered going back to some stock Michelins too, but don't know how they would look on a leveled truck. Information/opinions greatly appreciated. Thanks in advance!