Wonder if your not getting vacuum advance? If engine is just running on mechanical advance and the vacuum advance isn't working that will cause some hesitation at lower rpm. Does the vacuum gauge fluctuate at all? You could have a vacuum leak somewhere. What are you using for a fuel pump???

Last edited by TJ's Chevy; 02/10/16 12:36 PM.

1966 C10 292/tko600 http://67-72chevytrucks.com/vboard/showthread.php?t=596643
1964 C20 292/sm420