[oem4me]

I had the very same trouble with stumbling off the line even after a rebuild which included a new accelerator pump. I'll shorten the long frustrating story by saying you might have missed something.
Look down the throat of the carb with a good light source, jab the throttle, and you should see a healthy squirt of fuel into the throat. If you don't see that, your new pump is bad or its passage is clogged. The tiny passage outlet in the carb throat was plugged up in my case. One more trip to the work bench, a fine wire, more carb spray, and a few blasts of compressed air solved the issue once and for all.
Now if you DO see a stream of fuel, simply go over float level, ignition timing, wires, vacuum leaks, coil health, points and condenser, linkage wear, air cleaner, fuel pump, atmospheric pressure, ambient temperature, relative humidity, and astrologic convergence. You should be good. Lol.