I have the Nitto N555's and NT555R (drag radials) on my Chevelle,which also happens to be on 18x8/18x10's wheels....tires are 275/35's & 305/35's.Not too many miles on them yet so I can't report back on how well the hook up but I have Nitto's on one of my other cars and have always been happy with the ride and handling.
A plus for Nitto is that they are a pretty "square" tire and will allow a bit more clearance then some.
Got them from Jon @
www.driverzinc.com 