K&N Air Filters for Injector Stacks
Individual Round Style Injector Stack Air Filters
(Sold individually
unless specified otherwise)
K&N Air Filter for "Early Type" Fuel Injectors (Single Stacks) for Chevrolet, Etc.
Filters designed to fit with cut velocity stacks, or straight pieces of exhaust tubing. Rubber filter bases come with molded in velocity stack type radius and step, for smooth bore down from element to tube. Each filter has a rubber top with a stamped K&N logo.
| Air Filter Mounting Flange Inside Diameter |
Injector Bore Size Inside Diameter |
Air Filter Diameter x Length in Inches |
Straight Neck Mounting Flange |
5° Angle Neck Mounting Flange |
| 2-1/8" (54mm) | 2-1/16" (52.5mm) | 3-1/2 x 4 | RD-0500 | RB-0500 |
| 3-1/2x 5 | - | RB-0510 | ||
| 2-1/2" (63.5mm) | 2-7/16 (62mm) | 3-1/2 x 4 | RD-0700 | RB-0700 |
| 3-1/2 x 5 | RD-0710 | RB-0710 | ||
| 3-1/2x 6 | RD-0720 | RB-0720 | ||
| 3" (76mm) | 2-15/16" (74.5mm) | 4-1/2 x 4 | - | RB-0900 |
| 4-1/2 x 5 | - | RB-0910 |
K&N Air Filter for Kinsler Non-Siamesed Fuel Injector Stacks
Round filters fit uncut ram tube bells and clamp securely to the lip. Will fit any injection setup that has a minimum of 4-1/4" center to center, and parallel ram tubes. Each filter has a rubber top with a stamped K&N logo.
| Ram Tube | Filter Size | Injector Model | K&N Air Filter (Single) |
| 3-5/8" | 351-F-8 | - |
K&N Air Filter for Hilborn 4, Injectors Fitted to Honda and Kawasaki Engines in T.Q. Midgets
Air filters designed to fit over stock, uncut ram tubes. Filters come complete with rubber mounting adapters. To install, fit rubber adapters around ram tube bases and fit filters over ram tubes and clamp onto adapters in desired position. Air filters come with chrome end caps. Fits #45-K-4A and #45-H-4B Hilborn injectors and are packaged in sets of four.
Filters measure 3" O.D. x 6"L and fit 1-1/2" Ram Tubes. Set of four, RD-1004
K&N Air Filter for Hilborn Injectors for Blowers and Turbos
Air filters designed to fit over stock, uncut ram tube. Filter comes complete with rubber mounting adapter. To install, fit rubber adapter around ram tube base. On early screw-on ram tube type, cut adapter with razor blade and wrap around tube. Fit filter over ram tube and clamp onto adapter in desired position. Air filters come with chrome end caps.
| Hilborn Injector #525, for Magnuson Super Chargers. Used on Harley Davidson and V.W. blown engines. Filter fits 2-1/8" ram tube. Measures 6" dia. top, 5-1/2" dia. base, 6" long | RD-1100 |
| Hilborn Injector #523, for 60 c.i. Magnuson Blower Head. Filter fits 2-1/2" ram tube. Measures 7" dia. top, 7" dia. base, 6" long | RD-1200 |
| Hilborn Injector #524, for 80 c.i. Magnuson Blower Head. Filter fits 3" ram tube. Measures 7" dia., 6" long. | RD-1300 |
K&N Dual Oval Air Filter for "Late Type" Hilborn Siamese Stacks
Filters are designed to be used with stock, uncut, siamesed ram tubes. Comes with removable aluminum top plate. To install, push Ram Tubes through rubber base and clamp at desired height. Oval top plate measures 9"L x 5-1/2"W, total height is 6-3/4".
| Injector Tube Outside Diameter |
Injector Inside Diameter |
Injector Model# |
Center to Center Measurement of Bores |
K&N Air Filter |
| 2-1/8" (54mm) | 2-1/16" (52.5mm) | R | 2.44" | RD-4200 |
| 2-1/4" (57mm) | 2-3/16" (55.5mm) | Q | 2.44" | RD-4400 |
| 2-1/2" (63.5mm) | 2-7/16" (62mm) | P | 2.70" | RD-4600* |
| 2-5/8" (66.5mm) | 2-1/2" (63.5mm) | 327-C-84 | 2.70" | RD-4650 |
| 2-3/4" (70mm) | 2-5/8" (66.5mm) | 327-C-8 | 2.87" | RD-4669** |
| 3" (76mm) | 2-15/16" (74.5mm) | F | 3.20" | RD-4800 |
| 3-1/8" (79.4mm) | 3" (76mm) | 396-C-8M | 3.20" | RD-4850 |
* Adapter kit needed to convert the air cleaner when equipped with 2-1/4" restrictor stacks is # 85-4600, and kit
includes 8 adapters.
** Packaged four per box. When ordering singles specify #RD-4660 right side or #RD-4670 left side.
K&N Dual Oval Air Filter for Kinsler- Siamese Stacks
These air filters are designed for use with the Kinsler fuel injection system for Pontiac and Chevrolet small block V8. Air filters come with removable top plate, to install, push injector tubes through rubber base and clamp at desired height. Oval top plate is 9"L x 5-1/2"W. Total height of air filter is 6-3/4".
| Injector Tube Outside Diameter |
Injector Inside Diameter |
Center to Center Measurement of Bores |
K&N Air Filter |
| 2-5/16" (58mm) | 2-3/16" (55.5mm) | 2.80" | RD-5000 |
| 2-3/8" (60mm) | 2-1/4" (57mm) | 2.80" | RD-5000 |
K&N Dual Oval Air Filter for "Late Type" Hilborn and Other Injectors for V.W. Air-cooled Engines
Air filters designed to fit over stock, uncut ram tubes. Comes with removable aluminum top plate. To install, push ram tubes through rubber base and clamp at desired height. Oval top plate measures 9"L x 5-1/2"W, total height is 6-3/4".
| Air Cleaner Mounting Flange Inside Diameter |
Injector Bore Size Inside Diameter |
Hilborn Model# |
Center to Center Measurement of Bores |
K&N Air Filter |
| 1-3/4" (44.5mm) | 1-11/16" (43mm) | ARPM Rotary F/I | 2.700" | RD-4900 |
These filters are legal ONLY for racing vehicles. Not applicable, nor intended for use on emission controlled street or highway vehicles.
