[cj847]

I don't think we can answer your question without more information.

What distributor are you using? HEI or MSD? What MSD box?

I think 923 is the tach signal wire which would connect to a gray wire on a digital MSD box. Not sure on the old MSD boxes. You need to download the MSD instructions off the internet for your particular unit. The instructions are pretty clear.

On unused wires, I usually put a short piece of shrink tube on the ends after I cut them to whatever length I decide to leave. This will prevent accidental shorts or grounds. If you want a super clean install and are sure you'll never use the circuit, you can unpin the wire from the fusebox.