Originally Posted by jrexer
Does the same go with 3.31 gear option offered with the performance pkg?
According to your information you have a 2014, and is not the same as the 2007 for the original poster. From 2005-10 the V6 Mustang had a 7.5" rear end with open differential.
Starting with the 2012 model year all Mustangs have the 8.8" rear end and the Ford tlok differential. So your 2014 has the tlok and 8.8" rear end.