I pulled the distributor cap and.... well, I'm not sure what to make of this (note the bevels worn out at the bases of each wire terminal where the rotor's been striking them):


I also found some fine, powered metal flakes dusted all over the inside of the cap (which by the way doesn't look like there's been any arcing):



For grins I tried to line up the rotor (using the worn out spot where the rotor pivots against the coil wire contact as a guide) to see how close it was getting to the plug wire terminals, and... well it looks like a pretty big gap- about a 1/8" from the tip of the rotor going across to the face on the notch of the terminal:



Any ideas? I've seen caps where the arc would jump straight across to the opposide side of the notch and I've never seen this kind of wear before on the terminals. And I'm not sure if there's supposed to be that large a gap between the rotor and the wire terminals. But I might be wrong on this of course.