Thanks for the suggestion. The EGR was relitively clean, and I cleaned the IAC valve as well. The problem remained..BUT, I obtained a shop manual and I figured it out.
It seems that the power steering pressure has a lot to do with the idle control when the engine is at operating temp. I found leaking and cracked power steering hoses, as well as power steering pump seals. I replaced them all, and my surging idle issue is gone.
My Cimarron is an '86, lets see if these new hoses and seals last another 26 years.