Oil where it shouldn't be?

[CADreamin]

After splitting the work over several weekends, I finally completed a pretty good tuneup of my 98 GT. The car seems to run and idle significantly better, and doesn't seem to use as much gas...

One problem I noticed was during the changing of the plugs and wires. On cylinders 6, 7, and 8, when I removed the old plugs there was oil on the spark plug socket. It looked like fresh oil, which was just recently changed. The plugs themselves looked fine, as did all the other plugs and the old wires. The problem seemed to be confined to these cylinders.

My friend in CA had a similar problem on his SHO (not sure what year) and he had to have the valve cover gaskets replaced. When I look at the driver's side valve cover, there appears to be an oil leak near the bottom around cylinders 7 and 8.

Is this my problem, or do I have a bigger issue to worry about? The car runs fine, and doesn't seem to use an excessive amount of oil?

By the way, thanks to whoever posted the hint to use a long extension and u-joint to get at the #4 plug a while back. I myself used a combination of a short extension, then the u-joint, then a long extension to clear the bracket. When putting the plug back in, I also had to remove the rubber insulator from the spark plug socket and just be really careful when tightening down. The spark plug socket kept getting stuck on the plug with the insulator...

Thanks,