Ok updates, it.was.UGLY!
1. If this happens to you, take the time to build a drill guide for the broken bolt.
2. If you can't build a drill guide, do something to get the drill started in the center.
3. Don't depend on a "center drill"
So, I thought I got a good punch/center mark in the bolt. I didn't. I had some center drills and thought they would help get a hole started. The center drills walked. It's really hard to see what is happening, I was working in my garage, no lift, and it's almost impossible to see what is happening.
Once I realized I was off center, and, that I had a Heli-coil kit for a 10 x 1.25 I broke out the Dremel and started carving up the old bolt. That still took a TON of time, like HOURS!
So, if I had to do it over?
1. I would have been WAY more diligent once I was able to get a nut welded to the old bolt.
a. I would have heated the BEJESUS out of the combo welded nut/bolt.
b. I would have treated the bolt longer w/penetrating lube
c. spent a long time working the bolt/nut in and out in an effort to break it loose
2. It might actually be quicker to pull the engine! It took me at LEAST 6+ hours to dig out that old bolt.
pics attached