Mike...I ran some of my wires(when doing the big "hidden wiring trick") underneath other bigger wires that were already there. Another trick is run several needed wires inside a piece of rubber tubing (the smaller the better) and then branch the wires out from there.Piggy back the wire out of sight under vacuum hoses . Run the wire along the inside of the wheel well and then drill a hole in the lower part of the engine compartment  so only a small piece of wire is visible. Spray paint the wire the same color as under hood so it is not a " yellow and red stripe wire running along a flat black eng compartment".

Rtm,
I have the same situation as you did. Tach Is in series. Not enough juice for the pertronix and the car doesn't fire off. I could run an extra wire out to the coil but was looking to keep the engine bay stock. What did you do?
Thanks

Thank you everyone for the suggestions.
I am running a wire off the back of the ignition switch, through a hole (dimple) at the firewall, then wire loom wrap into the engine harness across the manifold and out to the distributor. Tediously, but will get 'er done! All this for electronic ignition- I hope it is worth it!