Crank bolt to hold damper

Helicoils are used extensively in the the defense industry in planes bombs & missles. A large portion of anything aluminum has helicoils in every threaded hole. One of the keys to helicoils is cleanliness so the adhesive bonds correctly. I have seen 3 inch helicoils. We ordered some that big accidentally once.

There is no vibration path through a helicoil. If the engine is balanced properly there is no vibration to transmit.