Yeah, detailed pics of everything are coming as I pull things out.

It happened over about 1k miles. It ran perfectly fine when warmed up, but I started to notice piston slap on cold starts, and it just kept getting louder every start. Also power output dropped off sharply.

Also, it was overheating badly towards the end. The headgasket was blown for sure on the Driver side rear corner, same location as dead cylinder. Probably warped the head with all the heat from combustion getting past the rings, or the extra friction from all the metal shavings everywhere.

Ironically, I still had 165 compression in that cylinder, and 180 in the rest.