Hi Midda, Rear guards need to have the lips rolled and not sure about turn in clearance with group s cars as they are restricted to 2 degrees camber. I run another alfetta with the same wheels but with 4.5 degrees camber and it just touches the firewall. I never ran that car in the pictures with the spacers as it was sold before i could test. If you are not familiar with group s rules, the wheels are a 14x6 and use 60 series rubber. Different types of rubber albeit the same specification are different in dimension. My findings are using the Bridgestone re55s. In regard to the front to rear track, check out MDs comments within this topic, He has a better explanation of the science than i am able to give.