Thank you for the info which was very helpful. I assume from the diagram that I can simply tape off the 8th wire (red with green tracer) if I decide not to use the 4-way flasher feature, right?
The 8th wire has nothing to do with the 4 way flashers. As has been stated, it connects to the park light terminal of the headlight switch.
You can dead end the 8th wire if you want to. However, if you don't change your front sockets to to use dual filament bulbs you won't have front park lights because you have cut the power to them when you wired the turn signals to them.
Why not just hook the red/green wire to the park light terminal of the light switch and dead end the original park light wire? It will take less time than changing to dual filament sockets.
By the way, if you do it your way you will need to dead end the wires you cut from the park light sockets to prevent them from shorting out when you turn on the headlights because the switch will make momentary contact with the park light circuit when you turn on the headlights.