WHY?

Been playing around with it tonight..all is well except for a minor little thing..with this SD intake, it has this very slight stumble off idle when stabbing the throttle wide open from idle..Its very, very minor..but it wasnt there with the original intake..any reason this single plane would do that where the dual plane iron intake didnt? Im not sure if maybe the big single plane may require even more pump shot than the dual plane did possibly?