Brad: Good move, the original W7Dc are hard to find. In my experience , the engines especially the earlier non transistorized ignition ones, run better with these original copper core plugs. I've tried the WR7 and WR9's but when the engine is tuned correctly, i.e. not too rich at idle, the W7's are best in my view.
Pete Lesler
1967 250SL
largely original