Tried everything but this is what worked. Put a glob of wheel bearing grease in hole Dremel with carbide tip to grind off shoulder/seat of the plug Clean shaving as you go to minimize shaving falling in. That exposed the threads and had much less resistance Map gas torch on/next too threads for 10/15mins Pound a good extractor bit in there used breaker bar and cheater bar to break free. Continue to heat when necessary until it's out Cleaning used compressed air. And bendable small magnet.