I would let the car warm up, in park and set it. Then, I would turn on lights, radio and heater, and select Drive to see how much rpm would drop for a load and adjust for a happy medium. That is, if rpm drops to say 600, then adjust idle up to 700, turn off accessories and see what the unloaded rpm registers. If it ends up being around 800-850, then I'd probably leave it. Alittle more advance on initial timing would help also, usually an extra 2-3 degrees.
If the idle solenoid was working and hooked up, every time an accessory turned on, the ECM would compensate by kicking open the throttle alittle.
The way it is suppose to work, set the idle for say, 750rpm, no accesssories turned on, then select A/C, the compressor turns on, and the ECM turns on the idle solenoid to increase throttle to make up for the load, hence, rpm is back up to 750.
Everett "An Engineer's mind is never idle."