...The 'not-so-obvious' differences between the street 911 and the racing 911 RSR. Take a look at the larger shock-tower housings used by the 911 RSR https://pbase.com/image/68078337 to allow the proper clearance for the larger racing rear coil-over shocks and springs. These RSR parts are significantly bigger in diameter than those used by the street 911, those larger coil-overs have to fit somewhere! ; )