Holley 122-58 Carburetor Standard Main Jet

These metering orifices control fuel flow into the metering system. They are rated in flow capacity &rdquocubic centimeters per minute” and are changeable for tuning purposes. The shape of the entry, exit, and size determines flow. All Holley Main jets are flow tested and then stamped with the correct number. Click on Catalog Product Page for complete listing of jets and sizes. Features Fits All Holley Model 2010, 2300, 4010, 4011, 4150, 4160 & 4500 Sizes from 40-110 1/4-32 Thread .057 Jet size Standard Main Jet Jet Hole sizes provided for reference only . All Holley jets are sized by actual flow and may vary from sizes above.