Unless I missed a prior post from you - no mention of timing fluctuations when in gear, and no mention of vacuum fluctuations when in gear. Hold the rods down when hot and idling in gear and see if things smooth out. ( take the springs out for this test ). Rods up = more fuel ( you don't want that at idle) - you state it runs down the road great with no surging or misfire that means you should be close on your mixture while driving - at idling the surge could be the rods popping up and or the timing fluctuations from the change in engine speed. Putting more timing in it may help too as long as you don't get detonation.