The Nutsert or Timesert (center) is good too. I like the top "flange" that gives a surface to tighten against. They are available in "oversize/oversize" when even the Heli-Coil failed.
I use the Heli-Coil (right) most often. Simple to use and works great in aluminum. If you follow the directions, take your time and get it correct, the heli-coil has saved people thousands of dollars and prevented lots of warpage from welding and high heat, trying to weld up and redrill.
All these motors I work on, usually have a lot of this . . .
Speaking of stripped threads . . .