I have 17x9 Cobra R's with 275/40R17's on the back and 255/40R17 on the front. I had 245/45R17's and it didn't look right on the 17x9 wheel and scrubbed slightly in corners, so I traded for some 255/40's which are shoter but wider, doesn't rub or scrub at all. I had Futura 275's on back originally, they scrubbed all the time, got the same size Firestone SZ50's and rides a lot better. I have my Quads flipped with the boots cut off.
I put 315/35R17 BFG Drag radials on my car once just to see what happened. It would roll, but scrubbed on the slightest turn or bump, so I took them right off. I have Topline brand Cobra R's.