[widebody911]

Well, I ended up replacing the plugs. I didn't want to, not because of cost (although it's double that of a normal 911 engine), but it's a major pain in the ass - I don't fit well into a 911 engine compartment.

I went ahead and replaced them, and the car seems to run better; I'll know for sure at the track tomorrow.

I guess I should have mentioned that these are the stock plugs - this is a 3.6L 1990 Carrera 2 engine.