3 pedals only!
Tires can fit on a range of wheel sizes, usually between 75% to 100% of the tire width. Using a narrower tire will help protect the wheel, and I suspect the wider wheels will likely have fitment issues. The ride is also a bit softer on narrower wheels.You can see this at tire rack. Go to any tire and pull up the specs, then look at Spec width which is the width of the tire when mounted on a wheel. You will see a 265 tire is as wide as a 275 when you are on 9 inch wheels. You just have to play around with the .2 correction factor which you can read about at tirerack as well.
As for performance, several autocross sites I visited indicated that using the widest tire you can fit on a given wheel width provided optimum performance, despite the fact that the sidewalls "balooned."