Mike, as you can see, the filter is very well protected in that it is burried inside the fender well. The filter only projects about 2" horizontally (toward the drivers side) beyond the drip sill. To prevent rain water from hitting the filter, I used an aluminum shield. The dimensions of this shield are 4" x 17". The flat region on the top measures 5" long with each angled region measuring 6" long. The angles were bent about 30* in my box and pan brake (a vise with some 2x4's would also work). In addition to these 2 bends, look closely at the top right hand corner of the aluminum shield in the picture. Notice how I bent up the back edge (the edge under and parallel to the drip sill) on the angled side region. You will also see, unfortunately, some blue silicone on the top. This is NOT siliconed to the truck. Rather, I siliconed a 1" x 5" piece of thin rubber to the back edge of the aluminum shield to act as a gasket between the aluminum and drip sill. Then the aluminum is fastened to the truck using an existing hole in the drip sill as shown above.
To secure the filter in place, I used a "strap" made from 2" wide by ?? long (raw stock was 2" x 36") aluminum. When you remove the factory air box, you will see a metal bracket mounted to the wheel well where the bottom of the air box was connected. I bent a 1/2" diameter "hook" at one end of the aluminum strap and hooked it into the factory mounting braket. Using the filter as a template, wrap the aluminum strap around it to form your curve. Referencing the bottom of the filter as 6 o'clock, wrap the aluminum clockwise to about 2:30 then a sharp upward bend of about 135* is required to match the fender well contour. The strap is then fastened to the upper factory air box mounting bolt as shown in the picture. If I recall, you will have to cut the excess length off the strap for a clean install. I hope I have been clear enoungh to give you the general idea of this install. I will be away from the computer this weekend but will try and post some simple sketches next week.
Regards, Marc