[Three Peaks]

Keep in mind that different manufacturers have different sized hoods, so plan accordingly. You will no doubt need to do some glass work to close up the hole you cut to remove the existing scoop before cutting the new hole.

On the Kirkham I measured, and the hole I cut in my hood, the opening starts 6" from the rear of the hood and is 14" long. The opening is 9 1/2" wide, so you will need to make a 4 3/4" radius circle at each end of the opening and connect the sides of the radii and you're ready to cut.
On the Kirkham the rear of the scoop starts 2 1/2" from the rear lip of the hood
I placed my opening on the centerline of the hood, but I'm not positive this is the correct position, since most engines set 1/2"-3/4" to the passenger side of the engine bay/ chassis.

Since the opening really isn't all that useful on most cars anyway, I placed it where I thought it would look best- on the centerline.

Let me know if you need any more help.

Bob