White smoke, pulling the exhaust manifold looks like water is leaking into the exhaust from the rear housing. Pulled the engine, don't see any breaks in the water seals. There's no other way for water to get into the combustion chamber other than around/thru the water seals, right?

 

I think I may have figured it out. One of my corner seals is cracked, so must've had a minor detonation event.