hey im having bad problem with carb, sounds common, though ive never had it before. 350/290 horse crate motor(new). EVERYTHING NEW. have professional products crosswind intake(dual plane airgap copy) msd hei streetfire dist. and holley 600 vac sec #80457. when i try to get on gas quickly it wont rev(go) unless i do it slow or feather it. if iget past that spot it does fine! sometimes it would spit out carb. no vac leaks 10-13in of vac and it is set to highest vac in on gauge. timing is right and adv is working (vac and mechanical) this flat spot off idle is driving me crazy can anyone help me?? it has 31 squirter and i tried 35 but it got worse.