Originally Posted by tyrslider
Actually you can helicoil it using m6 helicoil which requires it to be drilled larger for the insert (stronger than original). Which will allow the same size stud and require no further mods.
Oh yeah! Don't use anything but a tap handle or you'll ovalize the hole making it weaker!
Bingo! Thats what I did! It is probably the strongest fix for this problem.