I have searched this forum for the size of the hole near the dizzy. The machinist took the plug out when he did the block and I want to use the hole for my pressure gauge. I realized I didn't get the plug back until much later. Engine is already in and I can't seem to get the right size. I know several have suggested using this hole for the pressure so if anyone has info I would really be grateful.
Also would it be pipe thread or machine thread if I am asking that correctly?
Wade