The correct springs on the right look to be like a much stiffer spring than the springs on the left. Is there a noticeable difference in ride quality?
My local Les Swab has the Cobra G/T in stock in those sizes and will do a test fit for free. So if they fit and look right, that will work. Then it goes for an alignment right after tires.255/60 rear, 235/60 front
Or just stay with the 245 rear, but do 225-235 front
Not that I saw on tirerack.No 205 65 available? Or possibly even a 70?