I have a dual line Holley carb that must be 20 years or more old that I need to ID. I believe the number is: 3310-2 0124 As best I can tell it might be a 750 CFM but I cannot find the exact number in any reference.
You have got! You got a 750CFM Vaccum secondary carb there. Are they any good? Yes, there a good carb but a double pumper will make more power or at least thats what I have found. My car picked up about a 10th using the double pumper. Hope this helps