Riffraff Diesel 6637 7.3L Intake Filter Kit
This kit contains:
- Riffraff Diesel 6637 Filter
- Optional AFe Big Boost washable, or a Donaldson Blue® Filters
- Custom "Riffraff Diesel" Pre-filter Cover (Optional $29)
- Filter Adapter Tube
- 94-Early 99 Uses a 45* Tube
- Late 99-03 Uses a straight Tube
- SS T-Bolt Clamp

Late 1999-2003 Powerstroke production date 12-7-1998 and after
475 Reviews Hide Reviews Show Reviews
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Nice air intake
Mt stock filter housing cracked and dusted my turbo, To replace the stock intake box would have been stupid expensive even used. This Riffraff air intake was a lot cheaper, flows better, and looks a lot better then stock. Thanks.
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The whistle is real
Noticeable power improvement, can definitely hear the turbo now which is worth at least 50 more horsepower. Install was super easy, instant gratification, will be ordering more from RiffRaff soon.
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Huge Difference
Removed the Factory Air Box on my 2000 F250 7.3 Diesel and added the Donaldson Blue 6637. It installed easily and fit better after installing the Factory Driver Side Battery Tray (also purchased at Riffraff Diesel at a great price). I noticed an immediate increase in mileage and when I jumped on the turbo to make a lane change, I couldn't believe how well the old girl woke up! Push you back in your seat -- kind of improvement. I need to put a take or two more through her but I am getting more miles between fill-ups. Thanks Riffraff...
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Better thank stock
Good product. Just wish the shipping wasn't so expensive.
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Easy small boost in power
My 6637 kit went on a late 99 7.3. I got what I was expecting...very easy install, and small boost in throttle response and power. Any noticeable increase is worth this price tag in my opinion. Also as an extra little bonus, you get some cool new sounds from under the hood. Well worth it.
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Awesome filter kit
Easy enough to find a piece of 4” to adapt filter to stock intake. But this kit has it all included already. Got the donaldson blue filter and optional filter cover to prolong filter life. Installs easy and does exactly what needs to be done.
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Well worth the money
If you are on the fence about replacing your stock air intake, it is a must. This is finally a air intake setup that gets my 7.3 the air it needs
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It whistles!!!
Does great. A bit loud but I'm a redneck so I enjoy being loud and obnoxious!
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Make sure you have OEM tube
I replaced my AFE Stage 2 Intake with this kit + the AFE Big Boost Filter
Big improvement, at least in the cold months. Seems to let more air through, and better spool-up.
HOWEVER: Make sure you have the OEM intake tube (Riff-raff also sells this if you don't have it). I had to reinstall my AFE Stage 2 after taking it out because the 6637 kit uses the oem rubber hose, which I did not have.
I made a second order from Riff Raff, installed it in about 5 minutes, and its much better than the Stage 2.






