Need help finding one particular wire...

this is the diagram I used to sort this stuff out, I can't figure out how to get pdf's to post on here so you have to go to the website, sorry bout that:
http://www.tidewatermoparclub.com/TECH/ign_faq6b.pdf


You just did post it!!

Here's some good tech stuff:

http://www.mymopar.com/index.php?pid=31

A diagram for your 73:

http://www.mymopar.com/downloads/1973/73DartA.jpg

http://www.mymopar.com/downloads/1973/73DartB.jpg

A 72 complete service manual, wiring should be similar:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309