Quite a lag in posting time as a new member, I’m being moderated. But attached photo shows the obvious culprit. Didn’t realize a blown head gasket could mimic what I thought as a stuck / burnt valve. No smoke, no overheating, no coolant loss, no milky oil. Going to get the head checked. The motor has 7,000 miles since major rebuild in 2010. I’ve always ran non ethanol…. Any ideas what may have contributed to this? I plan on keeping the truck (I’m second owner) and putting more annual miles on it. Any thoughts would be appreciated.. Thanks