If they were stock wheels, Im told they would be 18x10.5 with 295 tires on them.
I wish I could convince myself to buy an LS1 F-body. I could afford it, if I sold my truck and the contour, but then I'd have two RWD v8 muscle cars to deal with in the PA winter. Funny thing is the F-body would get better millage than the contour or the Yukon.