I'm redoing the front fuel line hoses on my 1967 330 GTC (9303) and decided to go all in and replace the whole lot since I don't really know how old the back sections are and I have been using ethanol spiked gas. I know the two yellow wired lines from the tank to the electric pump, and the electric pump to the mechanical pump are M10, but I have heard conflicting opinions as to the proper size of the yellow wired lines from the Mechanical pump to the glass fuel filter and the filter to the fuel rail for the carbs. Some say M6, some say M8. I'm inclined to go with the larger (M8) unless I hear strongly otherwise. I have heard the M6 is for smaller, 4 cylinder cars like Alfas etc... but Ferrari V-12's use M8. What is the experience here?