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  1. #1

    Default 2003 1500HD cai mods

    I have a 2003 Silverado 1500HD crewcab with the towing package. It is similar to the 2500 in outward appearance. Under the hood is the 37/38 inch rad. It has the larger factory air filter. The factory fan shroud is (or was) very close to the throttle body. The factory air intake tube appears to be very restrictive because it must fit into a narrow space between the fan shroud and the throttle body opening.

    I have removed the factory fan, fan clutch and fan shroud and installed a Flex a Lite 282 electric fan and shroud. Now that the factory fan shroud is gone, I want to install a straighter flow CAI. My objective is to increase MPG and towing power. I do not necessarily want a louder intake noise.

    Should I just replace the tube and add a less restrictive filter to the factory box? Or would I gain more MPG by replacing the entire CAI? What will fit my vehicle? I certainly do not want to buy an intake tube designed to fit around the factory fan shroud. Any help will be greatly appreciated.


  2. #2
    Legend 2ToNe04's Avatar
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    Just replacing the tube will give you a gain, and more effectiveness because the filter is not what is restrictive its the tube but, usually all the filters cost from 20 -60 you might as well replace the whole thing. If your on a budget you should just get a tube.

    I would consider an exhaust so you can get all that fast air thats getting sucked in out faster, and a custom tune from our vendor, Blackbearperformance. they will do a good job tuning your efans and your truck

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  3. #3


    2Tone is right, to get the full advantage of a CAI you will want to do an exhaust system. For now you can make-up a tube and see how it performs.
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  4. #4


    Thanks 2tone04 and bob13 for the advice on the exhaust. But first back to the tube. What model Silverado(s) will match the underhood layout of my 03 1500HD 6.0L with towing package now that I have junked the factory shroud? Or are all Silverados the same under the hood?


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