Bigger tires...
Russ
Also, you'll want to install the wheels by jacking the rear axle as oposed to using a body lift ( your susp. will dangle and your tire will rest against the bump stop )
Again, make sure the wheels you choose (17x11's) are the correct offset. I can only speak for the TTII's and they WILL fit without clearance issues. I run 315/35/17 BFG DR's and they're the widest 315 DR I know of ... no issues at all (except traction
). 
