I bet it's a chipped piston at least, the bent plug is a dead give away. Happened to me like 3 years ago. Once I finally replaced my motor I found 2 chipped pistons, she still ran so smooth like nothing was wrong.
My car never normally sees more then 1-3* this time THE ONE TIME i drive it hard in months POP. I will just replace the piston(s) and hope for the best
2005 GPGT- Top Swapped Click me!15.5 @109
2002 GPGT- slow and stock
1993 Oldmobile 88- exploded the diff @158k GPF Resident Flowmaster Troll