You'll probably have to tear it down and carry to a machine shop to check pressure test everything.

 

Lot more than I bargained for...

 

How do you know for sure it's not a head gasket?

 

Not sure but head gasket was already done

 

I'm guessing, block cracked behind cylinder sleeve, cracked head, head wasn't properly skimmed and head gasket gave out again due to head being warped. Just thoughts and just trying to help but, have you removed the plugs in 3 & 5 to see if you have water in those cylinders or steam cleaned pistons? I had a misfire on #7 and when I removed the plug and turned the engine over it sprayed water everywhere but, I suspect mine was more sudden than yours. Mine was all at once with no small leaks.