I have notice lately after doing some additoanl performance work that when ever I get on it, my engine starts to bog or seems like I am not getting any gas.

this is on a 355 Chevy, holley 750 single pumper with manual choke, new aluminum top half and nice bottom half.

What could this be it really wants to take off but around 4000 it starts to bog, any ideas.

Bernie--

Fuel pressure, stuck secondary needle & seat, too high secondary vacuum chamber spring, intake to carb gasket interfering with secondary opening...