Well, now you're going to make me fess up in public. When I got my car to restore it had a fresh set of silicone wires and I didn't do enough research. Those wires are still on my car through the looms and caps and haven't had a problem. The plugs that came with that fresh engine back then are "R" plugs as well. I've got other problems at the moment. Engine runs fine and am dealing with one situation at a time.