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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Tons of Air
This kitnwas very easy to install. You can hear that turbo sucking air through the filter when you accelerate. Would recommend to anyone. Riffraff is on point as usual.
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awesome kit
I bought this kit because my truck had the recalled airbox still and I can't afford a turbo, was pleasantly surprised too gain 2 lbs of boost.
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works better than expected
Very easy to install. More airflow and better turbo whistle. Also a affordable price much better than other products that cost three times as much.
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Great addition.
I am pleased with my purchase and the ease of installation. Everyone loves it when they see it.
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Best Bang for the Buck
Best intake on the market for the price and Awesome company to deal with. Truck sounds a lot better now.
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This is a must have for seven threes!!!!
I have a 2000 7.3 all stock. I recommend you do a CCV mod before installing filter. Riff-Raff printed out the instructions for the 6637 install, and included a cool sticker for your truck. I had to do some minor cutting mods to the stock air box. I kept the plastic housing around the battery. The filter is big, and there is just enough room to house this thing after the stock box mod. I feel every truck should have the 6637. I notice a huge change when the truck winds up. This thing pulls a huge amount of air. More throttle response. This is a great priced kit compared to the 400 dollar kits. I got the black cover looks great with the engine. Top tier company Thank You Riff Raff!!!!
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Can definantly hear when its pulling air now
Installed after my turbo rebuild due to busted stock air box, and wanted more flow, works great, installed and can hear air being pulled in when the engine really starts working. im not sure about if it causes a difference in power due to the turbo mods being done at the same time but im sure it does help
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perfect air box replacement
Perfect for efficient replacment for the crappy broken airbox in my E99 7.3L, overpriced in my opinion but i took the hit anyways. I like the way it fits and the prefilter as well. Cool kit!
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Great product!
Got the 6637 kit installed yesterday. It made a heck of a difference over stock. Quicker spool up of the turbo as well as more boost. Also took it on a 60 mile trip after install and fuel mileage appears to have improved by at least 2mpg. I cant wait to get my FRx return lines installed today!






