DC tac hook up..?..

Here are pictures of my tach drive electronic distributor, part number P4120701...I got mine here on FABO back in 2011 from another member.... still sits on my shelf dammit lol

I have two new old stock clear distributor caps that I wanted to use on this but they won’t work, I thought that would always be cool on my car. I have a few tach drive Moroso tachometers and I always wanted to put this in my car... Old Skool is Kewl

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As I understand it that gear Drive has to run some kind of generator that the tachometer hooks to?..