I finally got to the bolt this weekend. I bought the cheap left handed bits at HF. As soon as I started drilling with the smallest bit I could see the bolt move. When I started drilling with the next largest bit it screwed the bolt right out of the hole. I guess I got lucky on my first, and hopefully last, broken head bolt. I de-carbed the head, piston and valves while I had the head off.
Now to get this thing running right. It starts right up but is missing and the governor is surging. Spark plug is new. Pulled the bowl and needles and sprayed with cleaner and compressed air. Needle holes are clean, still runs poorly. Guess I'll try pulling the carb and doing a proper rebuild. Finger crossed, I need to get some tilling done.
Thanks for all the help!