I was having similar issues with unsteady idle that was surging in D and N. Switching over to manifold vacuum at the suggestion of some guys here took care of that. Idle is now smooth and steady, and no more huge drop in rpm from N to D. I just have a stock replacement dizzy with pertronix though. I would like to learn how to adjust the advance curve with someones help in person though. I've seen it described many times on here but I like to be hands on with someone to guide me when doing stuff like this for the first time.

roe