The Flow Control System utilizes a newly designed base in combination with a unique lid designed to reduce intake turbulence. The resulting smooth, laminar flow enhances cylinder filling, horsepower, and torque. The filter element is the world famous K&N Filtercharger® for the ultimate in airflow and filtration.
The flow control system is legal in California only for racing vehicles which may never be used, registered, or licensed for use upon a highway. See knfilters.com for CARB status on each part for a specific vehicle.

K&N Flow Control System
2-Barrel Flow Control Systems


Circle Track Magazine discovered this model and featured it in one of their issues. That started the racers calling. Fits the very popular 4412 Holley 2-barrel by removing the choke assembly and leaving the choke tower untouched. Gigantic increase in air flow and lots of horsepower. The small block with about 340-360hp can expect up to a 15-17hp increase. In the 400-420hp range the range increase climbs up to 20-22hp. If your engine builder tells you that is impossible, just take one to him and run it on the dyno. Two sizes available and all the air you’ll ever need. Diagram of this flow control system.

2-Barrel Holley with Choke Tower

14" x 4.0" - 61-2000
14" x 4.5" - 61-2010

2-Barrel Holley without Choke Tower

14" x 4.0" - 61-2020
14" x 4.5" - 61-2030

Fits 2 barrel Holley with choke tower removed. Flows the same as 61-2000 and 61-2010.

Deflector Shield 14"
After watching all the work to create the Flow Control compromised by a badly designed wrap, it just seemed smart to control that part of the installation also. Designed to control heat and help the air flow.

4.0" - 85-54400
4.5" - 85-54450


NThe choice of quite a few racing associations. This carburetor is used in an attempt to equalize competition. If you have to use this carburetor, you “must” use this air cleaner. It may be the most trick piece we have. Clears the HEI distributor on the cast iron manifold. Only one size offered because only one size works. .

14" x 4.5" - 61-2040

Deflector Shield 14"

Designed to control heat and help the air flow.
4.5" - 85-54450


4-Barrel Flow Control Systems


The newest addition to the K&N Flow Control Air Cleaner line is specifically designed for all Holley Dominator carburetors, including Holley’s newest HP Series. This Flow Control Assembly takes full advantage of the 360? air delivery system by using K&N’s 4-1/2" Filtercharger. Using this assembly can produce a whopping 1200 cfm which will be more than enough air for any motorsports application! When it’s time to dominate the competition, this is the Flow Control for you!
14" x 4.5" - 61-6000


The inspiration for this particular air cleaner was the 390 cfm Holley. Many tracks and racing organizations use this carburetor as a restrictor. Flows plenty on the 390 and you can pass it all the way up to the mighty 850 and it keeps on making horsepower. Available in two sizes and complete with all parts necessary. Diagram of this flow control system .
4-Barrel Holley with Choke Tower
For those of you who have not modified your choke tower, this is just the ticket for your bracket car or late model sportsman.
Fits 390-800

14" x 4.0" - 61-4020
14" x 4.5" - 61-4030

Fits 390-850

14" x 4.0" - 61-4040
14" x 4.5" - 61-4050

4-Barrel Holley without Choke Tower

14" x 4.0" - 61-4000
14" x 4.5" - 61-4010

Deflector Shield 14"

Designed to control heat and help the air flow.
4.0" - 85-54400
4.5" - 85-54450

4-Barrel Holley Low Profile without choke tower

This air cleaner was designed for those installations with the carburetor mounted high against the hood. An engine that requires 700 cfm or more to develop a certain level of power just will not work with hood clearance that will only allow 450. There are race cars with less than 1/2" between the hood and the vent tubes of the carb. This model Flow Control is as low as is recommended to assure maximum air flow. In fact, it was necessary to enlarge the diameter to 16" to get the proper approach to turn the corner. Fits 390-850 Holley.
NOTE: This model works only without the choke tower and works great with restrictor plate engines. If you’re working with these engines, call the factory and get all the info. Available in two sizes with all necessary parts.
16" x 3.5" - 61-4500
16" x 4.0" - 61-4520

Deflector Shield 16"

The same effort went into these wraps as the 14" with the same results.
3.5" - 85-56351
4.0" - 85-56401


DescriptionFlg.K&N AssemblyColor
Flw Cntrl w/ 4Bl HolleyNo Choke66-3200Black
Flw Cntrl w/ 4Bl Holleyw/ Choke66-3210Black
Flw Cntrl w/ Holley Dom.66-3220Black
X-STREAM Flow Control Assemblies for 4-Barrel Holly Carburetors


These New Flow Control Clips are designed for added support around the outside of the complete assemblies. Made of spring steel and black powder coated these Clip kits come in sets of four (4) and are available for the Flow Control Assemblies listed.

Flow Control 14" x 4.0" - 85-83890
Flow Control 14" x 4.5" - 85-83892
Flow Control 16" x 3.5" - 85-83894
Flow Control 16" x 4.0" - 85-83896

Flow Control Clips and Replacement Filters


All of the air cleaner assemblies listed were developed as complete kits. A lot of time and effort went into each combination of parts and dimensions for the intended carburetor. Keep them that way for the best results!

14" x 2.5" - E-3735
14" x 3.0" - E-3737
14" x 3.5" - E-3745
14" x 4.0" - E-3730
14" x 4.5" - E-3732
14" x 4.5" - E-3732
14" x 5.0" - E-3760
14" x 6.0" - E-3770
16" x 3.5" - E-3804
16" x 4.0" - E-3806
16" x 4.5" - E-3808

Replacement Air Filter Element

Note: Legal in California only for racing vehicles which may never be used, registered, or licensed for use upon a highway. See knfilters.com for CARB status on each part for a specific vehicle.

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