Wow......what would I do????? RUN!!!
Why in God's name would he dyno the engine and then take everything back off of it. I can tell you why....because it was never put on in the first place. No one in their right mind would disassemble an engine after dyno-ing it. I just can not be made to believe that.
I really feel for you since you have spent a ton of money and I know that you would love to make him fix it, but you need to cut your loses and find another builder to fix it. Unfortunately you picked a turd for an engine builder. I would not waste anymore time and money on this guy. Take your stuff to a reputable builder. There are still a few of us that do what we say. Good luck with it.