So I've been doing some research related to the cylinder head failures of my newly purchase 2012 JK Rubicon with the Pentastar 3.6L. The build date of my Jeep is 12-21-11 so, it's well in the "red zone". The Jeep has 64,000 miles on the clock and there is nothing in the history report about having the left cylinder head replaced. During my research I've found information ranging from fear mongering idiots claiming 100% failure rate to people having over 150k miles with no issues. My question is this. Now that we are out of the extended warranty phase and these Jeeps are over 10 years old with a good portion of them reaching end of life, what is the actual probability of these cylinder heads failing? Was the fallout as bad as people made it seem early on or was it overblown? Should I have a new cylinder head on the shelf in my garage or just let it ride? Thanks for the clarity.