The air dams are the two blanking plates in front of the two front cylinders. They mount onto the lower inlet ramp reinforce angle and cover the upper portion of the cylinder to partially blank it and to throw some air over those cylinders.
They were always mentioned in the baffle instructions, but only seemed to be included in the last 4 years or so.
We have a rear mounted oil cooler - hangs off the back of #4 cylinder. The cut-out in the rear of the baffles matched what Vans showed, however, as we are in a cool climate - UK - we don't need that much cooling air and, with hindsight, the location isn't particularly good as it affects the cooling flow past the fins of #4. Also, the fact you have a large hole, bleeds high pressure air out the back of the baffles.
I experimented with speed tape initially, then made up a thin ali plate which completely closed the exit into the cooler. I made it large enough to fit onto the existing mounting holes - don't make the holes too snug, you are only trapping it between the back of the baffles and the front of the oil cooler.
I then trimmed it down at the top and put the two holes in. These were placed in line with free air, not air that has been past a cylinder.
If you don't have the sketches for the dams, PM me with an email and I will send some drawings and snaps.