So the cylinder 6 on my 07 mustang gt had a misfire. Went to midas to have it checked out. Turns out, the only thing holding the spark plug is the coil. Was given two options: 1. try to fix hole with a helicoil (cost: $400/was told there is a 50% chance it will not work.) 2. go ahead and replace the head for $2500. Helocoil option is a gray area: many have fixed it doing so, but there are those who don't like it. What do you guys think? Any other options? perhaps suggestion on shops instead of midas?