Originally Posted by ChrisSlicks

Yes I'm making the assumption of stock suspension for most amateurs. The Whiteline is somewhere inbetween the Eibach and the Hotchkis in terms of stiffness (both the Whiteline and the Eibach are adjustable). For a street tire stock suspension setup that is about as stiff as you would want to go. On race tires you'll want to go bigger, since there is more traction there is more weight transfer.