My setup is kind of interesting. Since I am using a Hitec digital servo on the throttle I programmed the servo so that its endpoints are at the points the servo starts to bind. This means that my AFR is 140 and ATV are 100. The ATV at the low end is only 90% since you need the throttle open a little for idle and idle trim adjustment... The idle kill pulls the throttle completly closed and kills the engine (I also have a FO kill on another channel). Setting the center point so that I get equal throw on either side has been difficult and the last time I went through this I didn't bother -- I simply set the center where the arm is perpendicular to the servo...

The servo is mounted 6 or so inches back from the carb in the engine box. I'll have to measure the amount of rotation of the servo arm from fully closed to fully open, but it is pretty close to 90 degrees...