I recently overhauled my engine and after having bored it out .030 and adding 1.6 roller rockers and adding a bit of a cam( not sure on specs, I was an idiot and lost the cam card), I am having an idling problem. The car appears to be running rich and goes through a cycle where it will appear to idle fine and then the RPM's will slowly drop and just before it stalls, the idle will jump up and remain high for a time. Not sure how long. Sometimes it won't come out of high idle either.

 

Sounds like your IAC needs reset ! Idle Air control !
I don't have FSM with me at work but I'll check the Haynes book.
I think you unplug it start the car Idle a couple minutes , turn it off plug it back in and turn on key but don't start for ten seconds turn off then start.
I f I have it wrong and find it i'll correct.
The IAC is located under the throttle body on LT 1 engines.
Another thing it could be is a Vacuum leak . If you have a gauge [ they are cheap ] you can check that and see if it's holding.
Did this start after putting engine back in or after it ran awhile ?
Sorry Haynes doesn't have it but I'll try to find it anyway.
I'm pretty sure though that's close to right !

 

What year is your car? Have you checked codes? Pretty tall cams can cause MAP sensor problems unless you have a reprogrammed ECM that changes the specs on the MAP.