Fuel and ignition revamping (solved?)

Well an update, 13+ volts at idle in drive with fans on. Set the timing back to 18* with lighter springs so the advance comes all in at 2500 -2800rpm. Took her for a decent cruise including a short stint on the freeway. Ran real well but again at extended idle in drive at stoplights the idle was odd. Noticed however that it did it even with the fans off. It would happen faster with the fans on but still would happen with them off. Curious...