Wheel offset question
I run 20x10 and 20x11 with PSS street tires and have run 17x11.5" for race tires on the rear. The offset needs to be correct for proper fit.
On my 10" the offset is 62mm. On the 11" it is 75mm. For you, with the 9" a 50mm offset will work well and for a 12" with a 79mm offset it should fit. This will move the wheel 1" in and 1" out. You need to confirm this for yourself as it is VERY tight and tires will make a difference in fit as will camber and how low your car is.
You can see the differences here -- http://www.1010tires.com/Tools/Wheel-Offset-Calculator
--Dan






