Allstate Carburetor is providing the carburetor tuning information about Holley carburetors. ACFI is happy to provide the specs many of you have asked for all compiled into 1 place. All of the parts listed below are available on our website. To locate and identify your Holley carburetor the number is located stamped into the front of the choke tower and will either start with the letter R followed by 4 or 5 digits. For example R-4776, or R-4776-1. The other way you may find the number is the word List followed by 4 or 5 digits. For example List 4053, or List 4777-4. Either way the id numbers are stamped into the choke tower. All of these parts are available on our website as well as more Holley carburetor tuning parts.The carbs here are 4150 mechanical secondary Carb numbers

4776 600cfm

Primary main jets 69, Secondary main jets 71, Power valve 6.5, Primary Nozzle 25, Secondary Nozzle 32

4776-1,2 600cfm

Primary main jets 66, Secondary main jets 76, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 32

4776-3,4,5,6,7 600cfm

Primary main jets 66, Secondary main jets 73, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 32

4777 650cfm

Primary main jets 71, Secondary main jets 76,Power valve 6.5, Primary Nozzle 25, Secondary Nozzle 25

4777-1,2 650cfm

Primary main jets 67, Secondary main jets 76, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 28

4777-3,4,5,6,7 650cfm

Primary main jets 67, Secondary main jets 73, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 28

4778 700cfm

Primary main jets 66, Secondary main jets 71, Power valve 6.5, Primary Nozzle 25, Secondary Nozzle 32

4778-1,2 700cfm

Primary main jets 66, Secondary main jets 76, Power valve 6.5 Primary Nozzle 28, Secondary Nozzle 31

4778-3,4,5,6,7 700cfm

Primary main jets 69, Secondary main jets 78, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 31

4779 750cfm

Primary main jets 75, Secondary main jets 76, Power valve 8.5, Primary Nozzle 25, Secondary Nozzle 32

4779-1,2 750cfm

Primary main jets 70, Secondary main jets 80, Power valve 8.5, Primary Nozzle 28, Secondary Nozzle 31

4779-3 750cfm

Primary main jets 70, Secondary main jets 73, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 31

4779-4,5 750cfm

Primary main jets 70, Secondary main jets 80, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 31

4779-6,7,8,9 750cfm

Primary main jets 71, Secondary main jets 80, Power valve 6.5, Primary Nozzle 28, Secondary Nozzle 31

4780, 4780-1 800cfm

Primary main jets 72, Secondary main jets 76, Primary p.v. 6.5, Secondary p.v.8.5, Primary Nozzle 31, Secondary Nozzle 31

4780-2 800cfm

Primary main jets 70, Secondary main jets 85, Primary p.v. 6.5, Primary Nozzle 31, Secondary Nozzle 31

4780-3,4,5,6,7 800cfm

Primary main jets 71, Secondary main jets 85, Primary p.v. 6.5, Primary Nozzle 31, Secondary Nozzle 31

4781 850cfm

Primary main jets 80, Secondary main jets 80, Secondary p.v. 6.5, Primary Nozzle 35, Secondary Nozzle 25

4781-1,2 850cfm

Primary main jets 80, Secondary main jets 80, Secondary p.v.8.5, Primary Nozzle 31, Secondary Nozzle 31

4781-3,4,5,6,7,8 850cfm

Primary main jets 80, Secondary main jets 78, Secondary p.v.8.5, Primary Nozzle 31, Secondary Nozzle 31