I grenaded my slant 6

That mighty nice of you Rob! Looks like the piston came apart and jacked the rod out the block. Amazing, members got 200K mile slants and your decides to go at 2K.
Yep, looks that way to me too. Like the piston stuck in the bore. This is 100% speculation, maybe it dropped a valve, which jammed the piston, which allowed the small end of the rod to break the crankcase.
Would be interesting to see the rest of the parts.