Reply to "The engine hesitates or bogs when I try to acelerate"

I took it to a guy who build dirt track engines. Used him because i did t want a comunity college mechanic working on it. The itital timing is at 14 and over all at 36. He suggested that we change the advance springs in my dizzy to one blue and one green.(msd ready to run). My carb is a new holley 750 and a edlebrock high rise i take.(got both from precisiom preformance). When he set the timming the vacum advance was not removed from the dizzy. It idles fine and runs smooth it only starts stumbling and fumbling when im moving. All new dizzy carb manifold coil plugs wires (fuel line and filter kit from (PP) also