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Holley

HOLLEY Pump Discharge Nozzle

MPN: 121-37 Catalog #: 001508784 Category: Carburetor Discharge Nozzles Check Vehicle Fitment

Product Details

Accelerator Pump Discharge Nozzle - 0.037 in ID - Tube Type - Holley Carburetors - Pair

Fuel Pump Hanger Assembly; For Use w/Die Cast Retrofit Billet Return 450 LPH Fuel Pump;

Do you have a Mopar, Ford or other type engine you want to install multi-point fuel Injection on? No, problem, the Holley HP universal retrofit EFI kits are designed to be used with any V-8 intake manifold. The kit comes with injector bungs and un-machined fuel rails so you can modify to fit any single plane 4bbl intake manifold. The HP universal retrofit kits also come with the necessary wiring, ECU, sensors and throttle body. Just select the fuel pump and Injectors of choice and you are off and running.

DETAILS:

Accelerator Pump Discharge Nozzle; 0.037 in. Hole Size; Tube Type; Incl. 2 Nozzles/4 Gaskets;

A good selection of accelerator pump discharge nozzle sizes is indispensable to the proper tuning of the accelerator pump system. The nozzle hole size determines the rate of fuel discharge. A larger hole will shoot the fuel at a faster rate, and with less pressure, than a smaller hole. Sizes are stamped on each nozzle. For example, the number 31 indicates that the nozzle hole size is .031-inches. Various styles of nozzles are offered by Holley.

Fitment: Accelerator Pump Discharge Nozzle 0.037 in. Hole Size Tube Type Includes 2 Gaskets

Part Number 12-137 SPECS:

Part Number 121-37 SPECS:

Accelerator Pump Discharge Nozzle - 0.037 in ID - Tube Type - Aluminum - Natural - Holley Carburetors - Pair

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 Accelerator Pump Nozzle
  • Accelerator Pump Discharge Nozzle
  • 0.037 in. Hole Size
  • Includes 2 Gaskets
  • Tube Type
  • PUMP DISCH NOZZ.037TUBE TYPE
  • CrbAclPmpNzz

Part Number 12-137 SPECS:

  • Diameter (in.): 4.800 in.
  • Fuel Type: E85
  • Fuel Type: Gasoline
  • Fully Open: 450
  • Material: Cast Aluminum
  • Thread Size: 1/4NPT
  • WARNING CA Proposition 65 Message: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
  • WARNING CA Proposition 65: Yes

Part Number 121-37 SPECS:

  • Material: Aluminum
  • Nozzle Size: 0.037 in.
  • Nozzle Type: Tube Type
  • WARNING CA Proposition 65: No

Accelerator Pump Discharge Nozzle - 0.037 in ID - Tube Type - Aluminum - Natural - Holley Carburetors - Pair

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
121-37
Catalog Number
001508784
Product Line
Carburetor Discharge Nozzles
Category
Fuel Delivery
Type
Carburetor Discharge Nozzles
UPC / Barcode
090127021002
Length
4.95 in
Width
3.45 in
Height
1.10 in
Weight
0.04 lb
Ship Alone
No
Air Restricted
No

Shipping & Availability

Current status 7 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: 7 available as of 6/4/2026.

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