Can ya tap it out and put a little bigger bolt? You can drill it out and put a threaded insert in it. I never have liked helicoils. Havent ever had alot of luck with wire wound up, but, one bolt doesnt have tons of pressure on it. The other two will take the load.

76' Volare, 5.9 magnum w/Iron heads. New best 10.68 at 123 mph 1/4 mile.