I routed most of my wiring under the fender aprons and some just below the upper lip of the passenger side valve cover as well as along the rail of the oil pan. The ignition coil,starter solenoid and coil were mounted under the dash on an aluminum plate.
here is mine, tach and other wiring runs along the top of the valve cover by the base of the intake....other than that it is strait forward..dissfigured, i also feel there are multiple possibilities to help your engine bay look better...check out the way my spark plug wires are run, its really simple using zip ties, weave one through and then run single ones across those to tighten then and it will really help clean up your engine bay...
Here's the underdash plate. Some of the wiring exits through the A/C drain hole in the lower firewall while the headlight, turn signal, horn wiring, fan, etc exits farther up the firewall and ultimatley under the fender apron
Explain to me how this is possible to resolve without getting a special distributor cap where all the wires are in the cap in the same order that they are on the plugs.
Everyone has spark plug wires crossing over others at some point.
Look at MustangMatt1966's engine bay to get a better idea of how to route the plug wires. Yes, you will still have one or two of them crossing one another, but you can turn the part that fits into the cap so that they do not touch. I only have one that crosses another, and I have about a 2" gap between the wires.