Holy crap.... changed spark plugs in the Corvette yesterday and I couldn't get one of the plugs to thread in. I spent about 15 minutes trying to get it started and nothing, It wasn't cross threading, it just would not start. Best of all the plug is one located under the AC compressor so I can't see what I'm doing as I'm working by braille. I didn't want to run a tap out of fear of metal filings getting into the engine. Spent the night not sleeping and having nightmares about having to pull the heads.
Anyhoo..... I found this awesome little tool to repair spark plug threads by back tapping. It worked like a charm and took 10 minutes. The tool works by extending through the spark plug hole and tapping from the inside out.
Powerbuilt 640811 14mm Back-Tap Thread Repair Tool
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