2013s with a driver's side head build date of 2062 and above have the latest revision head. any 2013 built before that date have an AB head.
You can read the build date from the side of the driver's engine head. It's a metal stamp located just above the exhaust outlet. the first line is the build date in julian.
2012 Deep Cherry Red JKU Sport S - Tickastar, 6 speed, 3.73, Dual Tops