I Have most of my parts to do my 475 over stock. For my drain line, I'm going to the valve cover. I have -10AN drain line with fittings. One fitting goes from -10AN to a 3/8 NPT. I have looked all over to find the correct size drill bit and tap. It seemed that a 5/8 drill bit will work. But not sure for the tap. The threads on the fitting seem to be metric 1.5. Diameter looks to be a 16 in metric.
What size drill bit and tap should I use?
Thanks in advanced for help.
What size drill bit and tap should I use?
Thanks in advanced for help.