Mopar Forums - distributor cap material and conductivity

While doing research for HEI retrofitting. I stumbled across a post on a website called 4x4ham.com

Apparently over there they call the HEI mod the "team rush upgrade" it seems.

Anyway, this section caught my eye:
http://www.4x4ham.com/showthread.php...nition-Upgrade

Quote:

Now, lets talk about the cap material it's self...

Black distributor caps usually use 'Carbon Black'
(Carbon Black = Soot from industrial manufacture, power generation, ect. Common coloring agent for automotive parts like plastic interior parts and tires, distributor caps, ect.)
To color the plastic.

CARBON IS A CONDUCTOR OF ELECTRICITY!

The cap is actually permuting the cross fires and ground fire problems!
If the cap is slick/shiny BLACK plastic, then look for dull, gray 'Carbon Tracks' inside the cap...
They will look like pencil marks or cob webs, just barely visible.
If you find them, YOU HAVE A PROBLEM!

...

If the cap has conductive carbon black in it, the problem is COMPOUNDED.

By using a COLORED cap (no carbon) and BRASS TERMINALS,
And spreading the terminals and ground access to the distributor housing farther apart, we are GREATLY increasing the chances the spark energy will go to the correct spark plug terminal!

I find this interesting, I assumed the color was purely for marketing purposes but, it has an advantage?

The truck I’m working on has a newer distributor and cap (maybe 2 – 3 years old). The cap is black. I could get a different one. There is a blue cap on rock auto made by United Motor Products part #CC811X. But, is it necessary?

The hei howto over at slantsix.org mentions to make sure the cap is in good condition and using a long tip rotor which has a brass contact 0.060 longer than stock. (NAPA Echlin Part # MO-3000)
ARCHIVE: HEI Electronic Ignition Retrofit How-To

I have purchased the long tip rotor but, am hesitant to install it since there is also a warning that some distributor caps contacts are ground off center, so there is a chance the rotor could hit them. I'm thinking if I can find a junk distributor I can use it to test compatibility between my existing cap and the long tip rotor as I don't feel like pulling mine.