I'm reaching the endpoint on the refurbishing of this old 1969 280SEL so when I noticed that it seemed to lag a little at low RPM I decided to check the plugs and then advance the timing a bit. All the plugs checked out except #4 which was a little wet. I then advanced the timing 4 degrees or so and test drove it. The difference was amazing. Lots of pep and good acceleration. I think I'll get a hotter plug for cylinder #4 just so it stays clean. What would be a good Bosch replacement for the W7 DC that I'm using right now? Any ideas out there? Thanks all.