Has anyone encountered this problem; my spark plug wire #8cyl started arcing and this isn't the first time I had to replace a faulty/burnt wire on my 1989 GT. I have an MSD 6AL and MSD TFI coil, would they contribute to a shorter plug wire life span? Is it just the heat? My headers are long-tube unequals and have plenty of clearance, I don't figure this is the problem. My timing is 14 deg. Anyone else experience this before? Any comments appreciated in advance, thanks guys.