Did not set ring end gap on kb107!!!

You may have been fortunate enough that the shop gave a hair extra piston to wall clearance. If I recall, the generic off the shelf rings I've used were pretty much on the high side. At this point, as said earlier, just keep it cool, don't throw a ton of timing at it and let it eat. You've gotten 7k out of it so far......at this point, i'd sleep well if it was mine.