I just purchased a '74 2002 with Weber 40's which the previous owner had just installed. I'm pretty sure the jetting is ok, since it was pre-jetted for this car. My problem is...The car coughs back through the #1 carb throat at idle, low speeds, and deceleration. I think the problem is related to the mixture screw on #1 cylinder. When you turn screw all the way in, it makes NO Difference in the way the engine idles. One other thing that may be contributing is a vacuum advance distributor which is disconnected. ANY IDEAS??? Thanks in advance.