I have a performer 600 on top of my mild build 350. I have 5 psi going to the carb through an electric fuel pump. From a dead stop when I stab it there is no hesitation, but if I gradually give it gas once I hit the mechanical secondaries there is a flat spot or slight hesitation then its ok. I havent messed with any of the jets or metering rods, or even the floats for that matter. Any suggestions?