by
Fuel
Injection
Performance Kits
(FIPK's)
Stubstacks
K&N
Stubstack®
INSTALLATION
The K&N Stubstack is designed to increase the airflow of carburetors,
by decreasing the restriction around the choke horn. The stubstack fits
inside the air cleaner housing and slides snugly down over the choke horn.
Install holding nut finger tight and use Loctite or 3M to seal. When installed
on some models, there may be a slight gap at the base, however this is
normal and will not affect the performance of the stubstack.
Due to space limitations between the choke horn and some air cleaner baseplates, the stubstack has two thin spots in the casting. These will sometimes crack or chip slightly, but does not affect the performance.
Because carburetor
castings vary, the stubstack will not fit all carburetors. Check the list
numbers for proper application. On some carburetors that are listed, it
may be necessary to alter certain areas on the stubstack. The polyurethane
material is easily filed and sanded.
AIR
FILTER APPLICATION
The stubstack is designed to only work effectively with K&N Filtercharger™
elements and 360° custom air cleaner assemblies. If the stubstack
is installed in an improper housing, the performance may actually drop!
The minimum height above the stack needs to be at least 1-1/2" for
proper operation. Check the K&N Custom Assemblies that will work properly.
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FLOW
BENCH TEST RESULTS
DYNO TEST: 5,000 RPM |
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"The original STUBSTACK™ hi-performance air horn will increase your engine's air flow up to 40 cfm with this simple bolt-on."
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HOLLEY
Square Bore with Milled Choke Horn
This stubstack is designed to be used on Holley 390-850cfm square bore carbs (4150/4160), that have had the choke horn milled off, but do not use an air cleaner. The full radius design helps to increase the airflow for drag racing. Will also hold down the base plate of a cold air scoop. Will not work with K&N Custom Chrome Racing Air Cleaners.
This stubstack is designed to be used with Holley 390-850cfm square bore carbs (4150/4160), that have had the choke horn milled off and still use an air cleaner. Eliminates the need for hand polishing and radius work. Will work with all K&N Custom Chrome Racing Air Cleaners, including Tall Velocity Stack Air Cleaners.
This stubstack is designed to be used on Holley 1050 & 1150cfm Dominator carbs. Will not allow use of a standard air cleaner housing, but it will hold down the base plate of a cold air scoop. Straightens airflow and helps even out the flow to all four venturies. Decreases the restriction around the throttle bores.
Fits most Holley 4150 and some 4160 Series carburetors with high and low choke horns. The 85-0200 is designed to fit 4 barrel popular models in this series. Holley carburetor list numbers are stamped on the choke horn.