The original head part number ended in AA if I remember right. I think they're on AC now...but people keep posting that they're hearing about new '13s having head problems as well. If that's true, they haven't fixed it yet. The "real" danger zone appears to be a manufacture date in the first half of '12; but mine was built in Feb '12 and I'm still waiting for it to strike.
Chrysler still hasn't fessed up to what the problem is. One common theory is a bad valve seat, another has to do with high temps from the exhaust manifold or something.
Utah Jeep Crew #148
No powerball here? How am I supposed to finance the mods?!?
'12 Sport...miss my YJ for all the wrong reasons though