I had the same problem with one of the bolt holes on my rear motor mount. JBWeld worked great for me and I had NO thread left. I had to tap it out again then mixed up some thin JBW and dripped iit into the bolt hole. When I screwed the stud in all the way the JBW was oozing out the bolt hole. It hasn't been a problem since and I check it regularly.
hope that helps

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Let the solution BE the revolution