I was getting a multiple misfire code p0300.
Did a tune up, now I'm still getting p0308 misfire on cylinder 8.
I pulled the plug, which I just replaced along with cap, rotor and wires to find oil along the threads, and looks worn. But it's only a few days old. Any ideas where to go. Also truck smells of burning oil, no visable leaks. 305 vortec