You do, IMO, want the shaped vents to point aft. Otherwise, they act as scoops and pull water into the bay. Any hole from the bay to the outside will vent heat. The engine bay is, relatively speaking, "pressurized" due to the fans and just the air being shoved through the radiator. Not to any large point here, we are talking millibar pressures. But still.
What I can tell you is that with both fans running the heat that gets kicked out of the bay is ferocious. On the right side, where the Ford fan lives, the heat that is rushing out of the Fender Well is staggering. The Left side that has the Stock fan, not so much which is leading me to see if there is any possible way to get another Ford fan in there. Have not checked yet but... I suspect that there is not enough clearance to take the fan. I will check though.
I bent the pans in my bench vise using some 1/8" aluminium angle stock to make the jaws. I used a combination of a leather mallet and my rubber mallet to massage the metal into place. Prior to any metal work, measurements were taken and a paper template was made. If you look at the vents, they are not square but are parallelograms. Also, they are pitched to direct the water flow. Used this as a teaching moment for my Kid. We, OK, HE took the measurements. I had him fire up my copy of AutoCAD 2012 and start the design. Once we (OK, I) was happy with it, he printed it out, folded it and did a test fit on the Kitchen table.
Then, and only then, were the holes were cut and everything installed. Fit the first time, no issues and was a good moment with the Kid. Being as old as he is, I do not get many of these kind of moments any more. He graduates with his BFA in December. Going to be a 3D Animator. Good choice that.
