looking for mechanical advice on a '97 GT...

[lil drummer boy]

Well I have a new problem now. Actually it's the same problem, but something I hadn't seen before. I changed out my plugs and plug wires. I changed them all one at a time so I wouldn't screw up the firing order. I changed the left side first and then the right side. Well all the plugs on the left side were dry as a bone as I'm guessing they should be, however all the plugs on the right side were covered in oil on the tops and bottoms. In fact, upon pushing the socket down onto the plug in the front right side oil spilled over out of the hole. Now I'm certain this isn't a good thing, but I went ahead and changed out all the plugs and plug wires anyway to see how it would run. One of the plugs did have a bent prong on it.

I started the car and it ran skiddish almost like the timing was off. It idled pretty rough and shook pretty good for a couple minutes and then it all evened out. After about 10 minutes of idling in the driveway the engine was running really smooth. I'm guessing it had burned the excess oil out of the cylinders? Anyway, I took the car out on a test run and drove it around for about 20 or 30 minutes to see if it would start missing again and it ran like a champ.

I was thinking that maybe I had bad piston rings and that was why oil got up on the plugs, but if that was the case wouldn't it have started missing again during the test drive? Or does it take a little while for the oil to foul the plugs and cause them to miss? Or am I possibly way off?