Wire hiding

[83gt351w]

Being disgusted with the wiring mess I was dealing with, I decided to start tucking. I pulled out the inner wheel wells, cleaned up 35 yrs of dirt, and got started. I am running the power locks, and defrost wires in the pass well, around the radiator support, to the solenoid the will be mounted in the drivers well, along with the pass headlight harness. Which leads me to a few questions.

Is there any reason not to move the duraspark box under the drivers seat? I noticed Basin Motorsports moves his computer under the pass seat, so I don’t see why I can’t. Just lengthen the wires.

Best spot for the coil? Or just leave it there?

Finally, I’ve identified every wire, except one that comes out with the harness, is solid blue, and appears to be a 12 ga wire. What’s it for?