V/P contact might be a possibility. If you have a borescope you could go in the plug hole & see. A valve might have been too tight in the guide & seized up.
I can steal a borescope from work on Monday
This sucks with a car show tomorrow and mostly sunny
Been working on this damn thing like forever when any free time from work
1971 Dodge Charger Superbee 2011 Ram Sport 1500 Quad Cab Deep Water Blue Loaded Siberian Huskies