Hopefully this helps those that are trying to figure out where to drill the large hole. I measured from the upper fender corner to the indent in the fender 31.125" (31 1/8"). I then took a bunch of measurements as you can see in the picture below based on the snorkel itself. But the ultimately from this first point the center of the hole to drill is about .375" (3/8") below the indent. Hope my chicken scratch helps someone. YMMV.
