IIRC, our struts can take just about a 27" tire with minimal rubbing. As for width and offset, I don't know that off the top of my head.
Edit: I think that 27" tire height works with a 215 or 205 sized tire. I don't think a 27" 225 series tire would work with stock offset wheels.
Edit: I knew I had seen it somewhere.
http://www.dirtyimpreza.com/forums/s...ad.php?t=25108