Some of us mount the coils up on or near the front down tubes .. and that makes it a no brainer how to run you plug wires.

But .. most of us don't ..we run them under the carbs or behind the motor or under the seat.. Therefore the plug wires need to be longer and have to wind their way up to the front of the motor .. Most of us simply run them over the top of the cam cover and down to the spark plugs .. Thats how I used to do it anyway ... (back in the beginning)... HERE, and HERE.

I never really cared for that "over the motor" approach .. but at first I couldn't think of an alternative .. Until one day I was laying on the ground fitting a set of pipes on a new build .. when i noticed I could see daylight between the cylinders ... there was a little gap between then .. about the size of a plug wire ... Since that time .. I've run my plug wires down the center of downtube and into those holes and the would come out the other side under the carbs .. right there for the Finch or Santee boxes that we used back then .. or you you could continue them on further back if thats where you have your coils mounted..

More HERE.