[Jack21]

You can do it either way. I have mine routed along the front of the valve cover, held in place with plastic (nylon) wire holders/standoffs from Summit. Looks neater (MHO) that way. If your headers are ceramic coated, they won't burn your plug wires either way. Using FMS 302/351W set and they fit fine, again either way.

That being said, I had the opportunity to compare the Accel 300+ race wires, and the FMS cores. The Accel cores are substantially fatter than the FMS, look like they'll carry a heavier amperage load, and last longer. Thinking of changing. Not as "Cool" looking as FMS, but my plugs might be happier.