pokapotato

I pulled one of the plugs out of the main oil galley on the left side of the engine. It appears that this is a metric o ring boss plug. I tired to install a standard oring boss plug and the thread pitch seems different. I would like to adapt from the metric o ring boss to NPT. Has anyone done this and can you provide any help as far as where to get the fitting. I am installing an oil pressure gauge and switch and need that adapter.