my 66 stang has been having some problems with idling ever since i bought it, i have the idle screw on the carb backed off all the way, but the idle is still way too high, so i mess with the distributor, i advance it and the idle starts dropping but the engine has no power, i retard it and the idle just gets higher, right now the lowest i can get the idle is 1400 rpms with power, car has new plugs, points, condensor, rotor, cap, wires, and a rebuilt holley 1v carb.... any suggestions?