/6 runs great, randomly stumbles and dies...???

Interesting. I heard about the possible MP orange box quality issue. The one I got with the kit is my spare, and I've been using an older (but new) USA orange box I had. I also have a brand new Echlin (NAPA) box. It only takes seconds to swap it out, so I may as well try that quick just to make sure (since I'm triple-checking the ground on it anyway).

Won't get around to working on the car at all again until next weekend at soonest because our garage/drive is all full of garage sale crap LOL