These metering orifices control fuel flow into the metering system. They are rated in flow capacity cubic 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

Product Features:

• Fits Models 2010/2300/4010/4011/4150/4160/4500
• Sizes From 40-110
• 1/4 in.-32 Thread
• 0.104 in. Jet Size
• Standard Main Jet