Why does 350 motor with four barrel carburetor hesitate when eccelerating?

Would help to know what type/size of carb, distributor, cam, year of vehicle and what mods.

Most important is what cam, if stock or a performance after market.

some causes could be

bad accelerator pump ( in carb)

weak fuel pump

bad gas

low float level

bad advance in dist (vacuum or centrifugal)

plugged air cleaner

plugged exhaust ( bad cat conv plugged muffler)

See why need more info?