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Holley

HOLLEY Main Jet Extension

MPN: 122-5000 Catalog #: 001508850 Category: Carburetor Jets And Components Check Vehicle Fitment

Product Details

Jet Extensions - Screw-In - 1/4-32 in Thread - Brass - Standard Holley Jets - Demon / Holley 4150 / 4160 / 4500 Carburetors - Pair

Main Jet Extension; Pair;

An improved jet extension design that actually screws into the metering block. The main metering jet then threads into the end of the extension. The installation effectively moves the fuel entry point for the main jet out into the fuel bowl. In this location it cannot be uncovered by fuel, causing a lean condition, during periods of hard acceleration or braking. 2 per package.

Fitment: An improved jet extension design that actually screws into the metering block. The main metering jet then threads into the end of the extension. The installation effectively moves the fuel entry point for the main jet out into the fuel bowl. In this location it cannot be uncovered by fuel; causing a lean condition; during periods of hard acceleration or braking. 2/Pkg.

DETAILS:

Part Number 122-5000 SPECS:

DETAILS:

  • Holley Performance Emission Code 5: This part is legal for sale or use on Emissions Controlled Vehicles; Uncontrolled (Non-Emissions Controlled) Vehicles; and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations
  • Carburetor Metering Jet Extension Kit
  • Main Jet Extension
  • 2 Per Package
  • Improved Design
  • JET EXTENSIONS
  • CrbJetExtension

Part Number 122-5000 SPECS:

  • WARNING CA Proposition 65 Message: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
  • WARNING CA Proposition 65: Yes

Vehicle Fitment

Universal or product-specific fitment. Please review the product details and contact us if you need help confirming fitment before ordering.

Product Specs

Brand
Holley
Part Number
122-5000
Catalog Number
001508850
Product Line
Carburetor Jets and Components
Category
Fuel Delivery
Type
Carburetor Jets And Components
UPC / Barcode
090127336779
Length
5.00 in
Width
3.45 in
Height
0.60 in
Weight
0.04 lb
Freight / LTL
175.00
Ship Alone
No
Air Restricted
No
Hazmat
No
Chemical
No
Prop 65
B
Non-Returnable
No
Case Quantity
1
Kit
No

Shipping & Availability

Current status 34 Available - Ready to ship
Estimated timing Usually ships within 24hrs

This item is showing available inventory. Most in-stock performance parts ship quickly, but timing can vary by warehouse, vendor cut-off time, holidays, and carrier pickup.

Inventory shown: 34 available as of 6/4/2026.

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