When I accelerate I get hesitation, I replaced the

It can be a few things that cause this.Mass air flow sensor,Map sensor,clogged fuel filter,timing not correct(cause by the knock sensor).I would replace the fuel filter first.Thats the cheapest thing.If problem still exists.Go to a local AutoZone or Pepboys and have them scan for a bad sensor code.Its FREE.Then replace what ever sensor is the problem

You might be running on one cylinder less due to missing spark (spark cable interrupt), poor gas mixture, which can be due to old gasket on the carb or some other air source like hose, just may need calibration of the ignition.