HUGE RELIEF !! The broken bolt was NOT a broken bolt. It ended up being debris clogging up the bolt hole. I had my copper tube & welder set up. But I also had (4) sizes of hardened left hand drill bits laid out, and decided to use my center punch to get my drill bit centered. I tapped the punch with my hammer, and the punch fell to the bottom of the hole. WTF... I cleaned the hole out with a pic, compressed air, a few drops of oil, and my thread chaser. (5) minutes later, starter installed, and bolts torqued. THANK GOODNESS! I knew I had not missed that before taking the block to the machine shop, and their block inspection sheet did not mention it. I assume it happened while cleaning the block. I had been stressing over this all week. Moving on...