Raque,
you beat me to it.....thats what i was thinking also, but i think you have to chase the threads for the coil to fit, so probably back to just tapping the hole again, and getting a bigger bolt. oh well
good luck with it bart. i would think it would be cheapest to just get a gasket, a tap, and matching plug.......the plug doesnt have to be oem. just has to stop the oil from comming out