If your having multiple leaks , it may be your installation technique. After the old plug is removed , really clean up the lip edge on the block and look for pits. I always use plumbers pipe dope. It's real gooey and doesn't get super hard and brittle . Start the new frost plug into the hole with socket that fits snugly into the frost plug. When you have the plug started, use a little larger socket or any flat face piping so it fits the lip of the plug and hammer in place . I use a piece of brass that I have cut to fit the plug. It's a lot easier with the engine out but I have installed plugs using the brass and air impact hammer while engine was in car .