Hunting Idle When A/C is On..?

95 4.6/130k miles Thunderbird.

I recently noticed that when i got my ac on, either max ac or ac, my car will literally rev itself. Basically a hunting idle. It will normally idle at a good 800rpms..no ac, with the ac on it will go from like 800..to850..to 800 etc.

Now, i just changed my plugs and cleaned my throttle body's intake plate, could these 2 things have effected anything..? ANOTHER thing, i recently refilled my ac system, with the normal R134...nice ac, good and cold, but the idle thing is weird.

I can live with it, but i just want to make sure thats not a common problem-if say a plug is misfiring or whatever.

Its normal. The IAC (idle air controller) compensates when the AC is on. If the computer didn't raise the idle when the AC is on, it would bog down to like 650 rpms. The IAC opens a predetermined amount to try to keep the idle speed the same when the AC is on. It normally hunts a little as pressures in the AC system fluctuate and the compressor kicks on and off by itself. Normal.