When i start the beast it idles fine. After a while it will start to idle rough in park. About 90% of the time when i pull up to a red light it will idle very rough and feels like its going to die so i put it up to neutral to bring it up a little bit. It drops to around 500 rpms when it is rough. Runs like a champ when im driving.

 

fuel filter, or fuel pressure regulator probably

 

Try cleaning the IAC valve. It is the idel controll valve on the side of the throttla body.