I just purchased a project car (NA-93) that runs OK (110K miles) but not great. I'm in the process of repairing a valve cover oil leak and during removal of the coil packs I noticed each coil pack shows what looks like to me electrical arcing deposit on the outer side of the coil winding that's right next to iron core, which is ground. I'm an old Chevy guy and what I know from the old HEI Coil that image I see on the coil packs tells me the coil are "breaking-up" or shorting to the iron coil to ground. What do you think?