Help me diagnose why my head gasket blew

I'll update this thread. I decided to pull the block and take it to the machine shop to have it checked out. When I built the engine a couple of years ago the machine shop was supposed to align hone the mains and square deck the block. Got a call from the machine shop a couple of days ago. 2 of the main bearings are ruined because the align hone wasn't right. The crank will have to be turned down 0.010" because of this. The deck is off from front to back top to bottom and bank to bank. So basically I am better off starting with a new block. So now I'm on the hunt for a 5.9 magnum block.