While not Mopar, this is a head from a Ford F150 5.0 motor. The dealer said that it had misfire codes, and they needed it looked at. Washed it, and vacuum tested the valves, but all sealed fine. Removed the offending cylinders valves and viola... My opinion is the gas is the problem, as the ethanol washes the seats of the intake valves, and exacerbates wear between the valve and cylinder. All 8 intake valves are junk in this head, needing replacement and valve job. I told the dealer that the other head has gone just as many miles, has drank the same gas as this head, and is definitely in the same condition, thus should be done also. They asked me to do two quotes; one head and both. The warranty service company would ONLY approve fixing the one head. I was actually surprised they didn't say to only do the one cylinder (2 intake valves and seats). This is normal for the dealers, the warranty companies will ONLY fix what caused the failure, even if it is only one valve.