Either I'm seeing things, lol, or your wires are already "MSD 8mm Heli-Core Solid Suppression Wire Ultra-Temp". The cores are still "suppression" material, it's just the coiled around stuff is thin solid wire of some form... Those are not solid plug wires per say, like the solid steel or copper core plug wires you can get. As well, MSD will never tell you their own wires are a no-no

Again, good luck with it