I've gotten 315/35R17 on my wheels, it rolled but rubbed with the slightest turn of the wheel, but otherwise I have always run 275/40R17's on the 17x9 Cobra R Wheels I have. Went through three 4 sets in a year and a half. I had to flip the quads and the pipes from the
Flowmaster American Thunder Catback did not fit, so I went with turndowns.
1st two sets were used Futura Ultra Z's from pepboys (they were free) They were not too bad as far as traction, I was about to cut a 1.99 60ft once with them, but on the street they were OK. They scrubbed the inner fender on sharp turns.
3rd set were used Firestone SZ50's, which had better traction on the street, no traction at the track, but handled and made the car drive soooo much better. They were actually wider than the Futura's but didn't scrub a bit. I highly recomend these tires for a street driven dialy driver.
4th set I have now, Nitto 555R's!!! They run thinner than other tires. In fact, they are the same width as my front tires which are 255/40R17's. Although softer, they don't scrub a bit, and OMG do they stick, not like slicks, but wow what a difference. Drivability and handling is better than Futura's but not as well as the Firestones, but they were designed for drag of course.
A 275 won't appear much wider on a 17x8 than a 255, but the sidewalls will bulge more, so I would recommend getting 255's unless for regular tires but Nitto's if you decide to go with 275's.