I have recently got done building my motor. Its a mild/medium build up and i wanted to get a holley double pumper for it. As I started looking I noticed that there are different classes of the 4150 4777 carb. Like 4777-2 and 4777-4 and beyond. I was wondering if someone could tell me what changes were made to the carb after each revision and which one would be good to get. Please help!
Thanks.

 

i have one on my cugar the different types have different jets plungers and boals also different types of chokes as well. if you have the base line one you can turn it to the one to the last. the type you have will do great for a mild build like yours it will do a good job if you decide later it you want to go with beater heads and a cam if you go insane then i would say upgrade it because it has room to spare.

 

i also forgot one of the numbers that you were inquiring has the ability to run the ethonal with out fouling as well. make sure the one you have can have small amounts of ethonal can go threw it. i am not sure if it can run larger amounts with out a upgrade to the card like to the plates where the boals conect i know the name but cant think of it right now. our carbs are fully upgrade able till insane mods.

 

i believe 4150 is the most popular one.