Do all 66 Shelby's have the 9" with the rear bump out or did some of the early non-carry over cars have the round back? I have a friend with a car with a December build date (maybe around car 300+- cant recall) and I assume it's one with the bump out (not round back housing) but figured you never know since his car also originally had overrides. Was there a transition date for the two housing styles?