[buelligan]

I have been on an adventure to find out how these units are made and what the failure mode was, I’m an engineer and a little part of me would not let this go. I was able to procure a “bad” cap from Ken Isidor of Ken’s Carburetors in Connecticut. (Nice guy, thank you Ken.)
A little clarification here, I want to lay out some terms so we all understand what I am talking about. The item in question is called an “Inner Cap” I will simply call it the “Cap”. The cap has two sides, one has a “contact” that makes contact with the rotor, and the other side is the “socket” that the ignition wires plug into. The combination of the socket, contact and cap, at four locations, I call the terminal. So I will be talking about the cap, the socket, contact and the terminal.
My plan was to map the connections for resistance, then once the “open” terminal was found I would machine the cap down until I could see the interface between the post and the socket.
The results of the Ohm test are by position identified on the cap, 1-6 .18 ohms, 4-7 44 ohms, 2-8 .17 ohms, 3-5 “open” (no continuity).
I set the cap up in a miller and milled down to just break thru the area of the connection between the contact and the socket. Here is what I found:

see pix

I again checked the continuity and found the circuit open across the terminal. I carefully filed down the material left by the milling operation and proved my suspicions, there was an air gap between the contact and the socket. I was able to slide a .001 feeler stock between the contact and the socket.

See pix

Now you may say, “The spark may jump that gap”, and I agree it MAY … But there are detrimental effects of the spark jumping the air gap, the contact points of the arc would build up carbon, thereby increasing the resistance, this would cause pre-mature failure of the cap.
Here is a close up @20X

see pix


I was able to secure an OEM FoMoCo and an OEM “type” Bremi Cap all of the terminals were checked for resistance and found to be less than .2 ohms.
Everyone I have dealt with in this case has been nothing but helpful and professional. I have nothing but good things to say about the suppliers I dealt with. This is in no way meant to be a witch hunt, rather a yearning on my part to understand what caused my frustration and waste of time that Saturday in September.