burnt spark plug wells

[feedmemustangs]

I Just bought a 98 eclipse spyder 2.4. It was driving with a hesitation so the first thing I wanted to do was replace spark plugs and wires. When pulling out the plugs I noticed there was oil on my socket. On top of every spark plug was oil, so I figured I needed a new valve cover gasket set. After I pulled off my gasket, I noticed that the outside of the sparkplugs wells were burnt, but there were all burnt a different amount. It went from like not burnt to more burnt, each more than the other in order from left to right. Sorry I wasn't able to take a pic before I put everything back together. I was just wondering is that normal?