Help with electronic ignition with MSD box and Tach Adapter

[Rutro]

It's been a while since I've been on here. At the begining of the Pandemic my daughter learned how to ride a bike and that was awesome. So, I was sidelined for quite a while, she loved riding, and I got interested in vintage steel mountain bikes. I think I've got that out of my system finally.
I'm back on my 70 Challenger, my dad usually helps me with electrical stuff, but recently turned 90 and he's not as sharp as he use to be.
I have 440 with automatic tranny. I have an Mopar electronic distributor, MSD coil and MSD box P/N 5300. I did check the forum postings and I get lost in the explanations.
As expected the stock tach doesn't show the correct reading in the dash. I do have the MSD Tach Adapter 8920. I have labels that my dad put on the wires except the male purple wire and where that actually connects into. The purple and the red wire must be co-located, because of length.
In one of the pictures with the chrome valve cover, there is a blue wire that comes out of the harness, does the purple go there?
Going to attach some pictures to help, maybe?

[Bullitt-]

  Not finding any info on a MSD box P/N 5300 ... The info in the link below my help.
   
     See the 6th post
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1849097/msd-tach-adaptor.html