Check with a parts store that caters to the professional repair trade, not one of the do-it-yourself places like Auto Zone. There are slightly oversize, self-tapping pan plugs that will cut new threads as they're installed. Dorman Products used to make a line of these plugs, but they've changed company names recently, and I don't remember the new name.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!