Get an oversize drain plug. Pretty easily available, they will cut their own new threads. They are pretty effective, I have had one on my Mustang for a dozen years. They are sold as just "oversize", eg. If your factory drain plug is a 1/2"x20 thread, you'll find one marked '1/2"x20 oversize' right next to it.
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'97 Honda Civic DX Coupe 5MT - dead 2/23
'00 Echo - dead 2/17
'14 Chrysler Town + Country - My DD, for now
'67 Mustang Convertible - gone 1/17
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