We laid out the general routing of the spark plugs and then marked an area to penetrate the rear baffles.
We found a nice support clip at Summit Racing which separates the two leads going the upper cylinders on each side. The aviation spark plugs give a hotter spark improving fuel efficiency and are 1/10th the price of aviation plugs. However, they are not shielded and EMag Air recommends that the leads not be bundled together, hence the separators.
The two small holes in Image 3 are for the right mag and fuel pump cooling blast tubes. The 2" hole is for the cabin heat source.
Laying out the routing
Creating an oval hole to route the two spark plug leads
Final Penetration - Black clip secures and separates the automotive spark plugs