[Christ]

Spill over? Not possible.

Where would it spill from, if you get all your oil in the oil fill hole? The spark plug covers are closed except a small vent on some aftermarket wires, there is a gasket between the head (valve) cover and the spark plug tubes, which you just replaced. There are also gaskets between the bottoms of the tubes and the head itself. There is no place where "spill over" is actually possible.

No offense, but please find a mechanic that either explains things better, or isn't going to give you a BS answer when he doesn't know something.

Although, he might have been saying something other than what I'm getting from the term he used... if that's the case, he should explain a bit better what he's actually talking about.