I've got a 1970 280se. As my mechanic tells me, it just runs rich and because of that, I replace the spark plugs every 6 months or so. It seems to run smoother and cleaner when i do this. However, I recently replaced them and I seemed to have lost power and my baby is running rougher now. When I bought my plugs times before, they were alredy pre-gapped to 32 how I needed them but I went back to pep boys yesterday and bought two more to check em and they are gapped to 44. So I think I'm going to take them out and fix this problem, however a friend just told me that he thinks that for some reason I shouldn't be using the washer when installing the spark plugs. I've never heard of this but I though it be worth investigating. Can anyone help a newbie out?