Big Block Tunnel Ram 660s Questions

Your idle speed is high because you are advancing the timing at idle by using the vacuum advance with manifold vacuum! Try this- set your idle speedscrews to expose the transfer slot(s) so they are square as they say, put themon the engine and fire it up and let it warm up, then measure your idle speed. Now pull that vacuum advance hose off and plug the hose temporarily, Your idle will go down.
Sorry for the lack of update here. I tried the square transfer slot setting with vacuum advance disconnected. It still idled at 3000. So, I turned it down to the appropriate idle speed. In discussions, it was determined that the fast mechanical ramp plus the manifold vacuum was too much. I removed the vacuum entirely. Just mechanical advance. 18⁰ ar idle and 36⁰ all in at 2200. I also added a 0.136 air bleed to each carb. All problems gone and got 11mpg on a 7hr cruise. It works amazing.