Heli-coil is not (always) a last ditch repair. Frequently they are used to improve the strength of original threads particularly in aluminum.
Installed from day one in things like the tensioner bolt hole in many alternators..
Drilling to the next larger standard bolt size, or welding and re machining are last ditch efforts.
Don't be afraid to use a Heli-coil if the threads are not perfect, it makes for stronger than original threads and being stainless you are less likely to have a bolt stick later on.
Grigg
