Classic/Antique Car Repair: 1966 corvette 327/350hp, octane boost, hei distributor

Question
Car is running too rich.  Have had the carb rebuilt, adjusted, etc.  Gas fouls the plugs.  Engine doesn't respond as it should from idle.  Engine does respond as rpm's rise.  Have added new coil, and converted to hei distributor.
Running highest octane at pump and adding octane boost as well as lead additive.  New wires and timing has been set.
Would like the engine to respond from the low end!  What do you suggest?

Answer
Jack;
  That is a good year 327  if there is nothing wrong with it , it should run good. I would check the timeing  what did you set it at.? .And as far as the plugs  i remember changing them  in my 63  327  at  least 1 x a mo. if they are black try to go one size colder and see if that helps. And i would check the valves out when were they last adj. you should have hyd. ones in that right.Is the choke closing up on you at take off or is it half shut ?