What's the ideal RPM range for idling in Neutral?

I hate idle speeds over 1000 and in a lot of carbs having it that high means you're no longer just using the idle circuits because the blades are open too far. I try to keep mine in the 850-950 range in nuetral and the "normal" rpm drop is only maybe 100rpm with a perforamnce convertor.
However, some very fast rate flat tappet cams will need a higher idle speed in order to gaurantee the cam gets oiled enough.