These were 245/40 Hankooks, I literally just bolted them on, no issues at all. Rear ride height is fairly low. I had a good bit of room between the wheel and fender, much more room in the rear than the front. It was getting close to the trailing arm though. Running 17x9 et42 with a 255/40 might start to get tricky. Did you swap a different subframe/trailing arms when you did the engine? Some of the Z3 trailing arms stick out further and could cause wheel fitment issues. __________________ ~Dave~ 98 328ti Morea Grun slicktop 11 128i space gray slicktop 13 JGC WK2 Deep Cherry Search | RealOEM |