I recently installed an AEM wide band sensor to help tune my carb. The car runs and drives and we just went for a quickie drive around the neighborhood. Some notes about its current condition. Engine spec is in my signature. Carb is a 36 DCNVA, very similar to a DCNF but with a manual choke. The engine idles high. While driving the wide band was reading in the 10-11 air/fuel ratio, very rich. Now that I have the sensor, I adjusted the idle jet, to raise the ratio and reduce the fuel. Idle jet is all the way in and its idling really high. I did not plug in a timing light or more accurate RPM reading. throttle screw is all the way out (not touching). It's idle at about 3000 RPM but still only at about 12.5 A/F. The exhaust is also a bit on the black side, which if rich, would be unburt carbon deposits? Do I need a set of larger or smaller number idle jets? Anything else possibly wrong?