On this cooling discussion, on thing I just noticed this last weekend while troubleshooting a popping/rattling issue, I took the cowl off the top of the grille, which allowed me to look in, on the top of the radiator/coolers. I should have taken a picture of it but I failed to. First, between the two radiators (I have the HD tow), there was large amounts of cottonwood and airborne objects stuck between the two radiators. Given that there's like an inch between them, I see no way to effectively clean that, so I'm guessing it's reduced efficiency.
Also, the smaller of the two radiators, likely the tranny cooler, is this insanely thin and flimsy plastic one. Felt like a complete piece of junk, was kind of nerve wracking.