I would never pay money to have wire that says what it’s for on it. I thought that was why you use different colors? Plus how will the harness maker know what stuff you plan on?

I’m wiring my 54 dodge pickup right now. It has a big block with an electric fan and I decided to run a mechanical oil gauge and an electric water temp gauge. I’m going with a foot stomp high beam switch and the dash has amber turn signal leds and a blue high beam indicator, but no neutral light or oil pressure warning light.

I write lists of what wires go where- thru firewall, to keyswitch, front of motor to firewall, firewall to tail, to nose etc. Then once it is all sort of figured out I make all the runs with the ends installed- ring terminals, headlight plugs, etc. once the runs all have one side done you can loom or tape it all up then install connectors or solder & shrinkwrap it all together.

There is usually a whole lot of zip tying everything at the end to keep it all tidy and I like to use blue painters tape both to group wires together and to make labels for the ends of the wires. I keep lists of what colors the wires are for each run also for future reference.

On my ‘54 pickup I re-used the column from the 89 dakota that also gave it’s frame and front suspension for my project. I completely gutted the column and shaved all the bosses off it for the ignition shifter and turn stalks. I think late model columns look cheesy in old cars. I moved the key to the dash and modified the ‘54 turn signal stalk so it would bolt to the smoothed column.

The d150 should give up a good fuse box you can re-use. Just figure out which busses will be constant hot and which will be powered up by the acc and run circuits on the key.

Good luck- sounds like a fun project! Post some pics of the mockup if you can I’m not sure what you’re going for.