Your local parts store will probably have them. If not, there are dozens of them on Ebay. Once you get the leaky plug out, clean the block bore with sandpaper and install the expansion plug dry- - - -no gasket sealer. It needs to get a good bite on the block.

www.ebay.com/itm/335578967293?

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!