While I don't know what engine, I imagine the location isn't drill and tap for helicoil friendly. If I had to pull the LA timing cover to install the helicoil I would more likely replace the cover.
It'll be wise to dial up the low side of the pump eccentric and draw the 2 bolts up evenly so you don't cross thread and/or strip another.
You now know that one bolt hole in cast aluminum is weaker than the pumps return spring. Good luck with it.