overcarb'ed super six??

So I spoke with a tech guy from Barry Grant, and he said he didn't think that the carb is too big for the engine. And he said with my problem(car will run with the choke on, but wont run with it off) that I should check my ignition setup and rejetting the carb would do nothing(he said the jets dont effect idle). I know my ignition system is up to par(above par actually). The only other thing I can think of that could be a part of the problem is what underneath the carb. I had to use an adapter to make the holley pattern fit the manifold. Now, the adapter is an open pendlum, and the intake is not. SOO...if you pull the carb off and look down the adapter, its obvious that the holes for the carter(way smaller and closer together than the demon's butterflys) are really just blocking airflow. Could this be the problem for the engine cutting off after the choke disengages? Right when I installed the adapter, I saw the potential to grind out all the extra material, but didn't want to take the manifold off just to do it.