I bought the K&N kit, cut a hole in the inner fender wall with a holesaw, and made my own heat shield. At highway speeds my intake air temperature is equal to ambient temperature, at idle when in traffic is at most 8 degrees F warmer than ambient. I noticed both performance, throttle response, and mpg increases with the use of an aftermarket intake kit. Then again, I have more mods downstream than most, 75mm MAF sensor, throttle body, headers, cats, exhaust, so the synergistic benefits I see from the addition of such an aftermarket intake are greater than those experienced by those who have nothing else done but the intake.
That said, it's a great mod and good place to start. You'll be able to suck in more air (it's up to you how "cold" depending on the degree of heat shielding used), and the air will be less turbulent due to the more solid nature of the intake tube (hard plastic, or metal as opposed to the stock rubber intake tube). Why let your truck breathe through it's teeth when you can give it more air? Happy modding!
