Riffraff Diesel 6637 Filter Kit

Part Number:



Riffraff Diesel 6637 7.3L Intake Filter Kit

This kit contains: 

- Donaldson 6637 Filter
    - Optional AFe Big Boost washable, or a Donaldson Blue® Filters
- Custom "Riffraff Diesel" Pre-filter Cover (Optional $35)
- Powder Coated Adapter Tube 
    - 94-Early 99 Uses a 45* Mandrel Bent Tube
    - Late 99-03 Uses a straight Tube
- SS T-Bolt Clamp


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  • 5
    Shipping was crazy fast!

    Posted by Cody Rutland on Dec 10th 2018

    Order Friday afternoon, it was on my doorstep early mon morning. Honestly didn't think I would notice much of a difference from my K&n, I swapped out the old filter for the new 6637 kit, which was as easy as loosening a few screws, the cover looks great, I went for the black one, as after I got it tightened I took it for a spin, let me tell you, I was pretty freaking shocked actually, my 96 7.3 dually was a little slow off the get go, now I can actually feel the turbo getting what she wants and the boost is awesome, definitely buy this product if you are questioning it!

  • 5
    Simple and effective

    Posted by Scott on Dec 5th 2018

    Does a nice job at using the 6637 filter. The pre filter sock is a nice touch.

  • 5
    Good product

    Posted by Zach Schilling on Nov 29th 2018

    As always, riff raff always impresses me with good quality parts, excellent customer service, and quick shipping. This filter (the Donaldson blue) not only looks good but out performs the k&n filter that was on the truck prior to me buying the truck. Touches the hood a tad but hasn’t given me any problems. If you’re concerned with it touching you’ll either have to cut away some excess plastic or buy the aftermarket battery shelf. Overall great product and gives your truck a little more turbo sound and a little more power.

  • 5
    6637 Donaldson Blue

    Posted by D. Mo on Oct 26th 2018

    Super easy to install this great product!. Thanks Riffraff!!

  • 5

    Posted by Mark on Oct 4th 2018

    1995 7.3 92,000mi
    Works great! It fits perfectly and looks great with the black dust cover. Remove old air box and kept it since you can hardly find the factory air boxes for under 200 dollars. Didnt hear any turbo noise change but the truck already had 4 inch exhaust straight with a 7 inch tip. Opened up the exhaust so I had to give the truck more air! Love this upgrade and will buy all my filters from riffraff from now on!

  • 5
    Great Fit

    Posted by Chris on Sep 12th 2018

    I needed a new air filter for my 1997 7.3 and didn't want to spend an arm and a leg on a Cold Air kit that may only provide slight gains. This kit was very affordable and easy to install, plus I can make modifications like a heat shield later

  • 5
    Excellent product, donaldson blue made exclusivley for Riff Raff..

    Posted by Jon on Sep 9th 2018

    Very happy with filter... Excellent filtration, fit , performance,as well as look..

  • 5
    Honest service and high quality parts

    Posted by Unknown on Sep 8th 2018

    I have a late 99 7.3. It is stock /195k. Always had excellent care and service. I purchased the 6637 kit because my stock filter box was not sealing good any more. This kit fits perfect with the new battery tray. I recommend the new tray as a must! Cleans up the driver side a bunch and let filter sit correctly. As far as performance goes , I did not see huge power or fuel mileage gains. That’s what tuners , bigger injectors , turbos and bigger exhaust are for. Having said that I conclude this kit does exactly what it is designed for. Keep dirt out of the turbo while allowing clean air in. One other product that is Awesome is the HPX. World of improvement in starting and smooth running!!!

  • 5
    Very Simple

    Posted by Unknown on Aug 29th 2018

    Product works as intended, really easy install, and truck seemed to pick up a little faster than before and I now know there is a turbo. Order was fast.