Firewall routing questions and points distributor wiring for the purests 71-C10 A/C

[71CHEVYSHORTBED402]

This was converted to HEI, and the guy ran the wire through speedometer cable hole. Same thing for a kill switch (never mind two 10 ga. wires for a CB). Won't fly with the rebuild. I'd like this truck returned to its factory glory less the HEI, and would appreciate any input on.......

A. Where/how do you recommend routing the HEI wire? I believe they should be 10 gauge wire. Is there another spot for say a 12 gauge wire (e.g., kill switch)? I guess I'm looking for "spares" through existing grommets, which may not be an option, but probably is because.......

B. This truck doesn't have a tach or vacuum gauge, and I'm not likely to install either. Where were these routed through the cab?

C. How were the original distributors wired?....the power, not firing order. I imagine they ran to the ignition right? If it came through the cab then where?

Descriptions work, but pics appreciated as well.

Thank you