I'm working on a 97 grand marquis and going through the ignition system, Im wanting to upgrade the coil packs and wires. Thinking about the msd packs with the ford racing wire set. I am confused however as to which spark plugs would be the best to get for this engine. I know a lot of y'all are partial to the motorcraft or autolite plugs..... and I might add I am planning a pi upgrade by summers end if that matters.