just rebuilt runs bad

i have had edelbrock carb issues that has caused the exact issues you refer to ,brand new out of the box. backfire, misfire, flooding,lack of power etc etc. do you have a solid 5-7 lbs of fuel pressure? try a different carburetor, try a regular electronic distributor and box.make sure your ballast resistor is conncted to its correct terminals. its sounds to me like it is ignition/fuel issues and not in the build. if it is running and you have good oil pressure and temperature, and it doesnt sound like it is going to come unglued then i would go through everything that makes it run if you have already pulled the cover and made sure that the timing marks are looking exactly eye to eye,and stabbed the distributor and wired it correctly starting with the rotor on number one and have gone the correct rotation on the cap.i apologize if i missed something in this thread that you have already tried but this is my 0.02$