I have a 1980 Chevy K20 with a 5.7L 350 V8 in it that I am working on. I got the truck running with the old carb but the choke is sticky on it and it doesnt run 100% unless I hold the choke open with a pliers. A friend gave me a carb off an old truck that is very similar but different. They are both quadrajets. The old was a mechanical choke and the new is a electric choke. I installed the carb with the electric choke and I got the truck started up fine but it ran somewhat hiccupy. There are a few connections in which in not sure where they go.



I am not sure where this connection goes too. The old carb did not have it at all.



In this picture you can see that the primary choke vacuum is not installed. Can I just pull the old one off of the old carb and install it on this one or should I order a new one? The top barb above the fuel filter goes to the primary choke vacuum as I understand. What does the barb on the bottom go to? Also the J shaped metal tubing is not used with this choke. What should I do with this connection?

These are the only things left that I have not figured out how to connect. Is it worthwhile to get this carb fitted for my truck or should I quit messing with it and just get the old carb rebuilt?