The spacer isn't going to work for me because I am already too close to the hood, even with a dropped air cleaner. I'm not sure what that would do for me anyway because the coolant would be cold still. Maybe I'm missing something.
I just checked the cap and it is flawless. All of the terminals look clean and nothing is built up on them.
I started the truck in the garage with the doors closed (don't try this at home) and lights off and couldn't see anything arcing. It was pitch black and I looked very closely.
I'm using a Mallory HEI billet unit with MSD wires. All is new.
The theory behind the Marvel Mystery Oil is that it will free up a lifter if one is sticking? At this point, I'll try anything.
I just tried unplugging each wire with a vacuum gauge connected and the problem goes away so fast I couldn't get to all of them before it went away. I'll try again either later or tomorrow.