Electrical MSD box wiring for an 88 GT- few questions.

Hello all I have a 1988 Mustang gt. It has been carb converted by a previous owner.

I am in the process of hooking up an MSD digital 6al box so I can have a rev limiter. I have a couple questions on the hookup.

1.) I need a good source for an underhood switched power. Where is a good place to pick this up at?

2.) From looking at the wiring diagram in my Haynes manual I believe the red with light green wire on the coil is the positive side of the coil. Does anyone know if this is correct?

3.) The factory tach currently works and I want to keep it. Do I run the tach wire off of the MSD to the negative side of the coil?

Okay guys, just had a thought. Since I am not using the factory wiring going to the coil any longer, can I use the positive wire off of the factory coil connector for my switched power to the MSD box?

Blown88GT said:

https://documents.holley.com/8874.pdf

https://www.holley.com/products/electrical/harnesses/parts/8874

Click to expand...

Hmmm, I like the simplicity of this harness but not sure if it would be right for my setup. My car is carb converted, I installed a Duraspark type distributor- because I want vacuum advance. I think I would still have to wire in the magnetic pickup. I still think it might be best / easiest to make my own wiring off of the MSD box wiring harness.

I have started wiring the MSD box based on the diagram attached, provided to me by AeroCoupe. It appears the red wire is connected to the positive side of the factory coil harness as the switched power. Am I reading the diagram correctly?