Hi all. I'm needing to clean out my head stud holes in my cylinder block and looking for an M12 tap to use. With There being so many types I'm not sure which one I need, I know it will be an M12, but then what pitch is needed? 1.0,1.25, 1.5, 1.75 pitch. Also what type of tap would I use? Amy links would be great. Many thanks.