I couldn't figure out how to delete this post, so I'm redoing it for clarity, just in case someone else ever wonders if a light sparkle at the boot is normal or not. When I recently changed the wires (Bosche $60 a set) and plugs (E3s at $60 a set too) I thought I'd do the dark test and look for any electrical disturbances. (My new place has a garage that can be completely dark with plenty of ventilation.) I was surprised to see arcing on a couple of wires, and a sparkling going on somewhere between the boot and the engine block on a couple of other wires. I couldn't really pinpoint it because my eyes would adjust everytime I turned on the flashlight. I need infrared or something to say for sure. I couldn't see sparkling on some wires, but figured that their location might have prevented a clear enough view so I assumed they were all doing it.

I took off the wires, crimped them a bit, used dielectric grease and used a cotton swab to coat the inside of the boots. I got the arcing to stop, but that sparkling at the boot was still there.

Wondering if it was the E3s I got talked into, I bought a couple of other brands of plugs... a NGK and an Autolite, one of each, and popped those into a cylinder I had a clear view of. No change. Still a sparkle at the boot.

Upset, I bought an MSD wireset for $150, this took care of it. The MSDs, when properly seated, did not glow or arc. I did loom the crap out of them to make sure they didn't touch anything metal, or another wire. It's running great now and dark under the hood where it should be.