Truck Only Starts When I Pour Fuel Down The Carb

I’m going to try to be detailed on this, I had a 2.5l fuel injected engine in my s10, it didn’t run so I swapped it out for a 305. I put airbags on it and when I did, I had to get a fuel cell because the stock gas tank didn’t clear. It was running just fine out of a gas can that I had the pick up and return hoses ran into. So once I got my fuel cell I put in the back of the truck but I wasn’t getting fuel anymore so I then tried running out back out of the gas can which didn’t work either so I decided that it must be my mechanical fuel pump, so I replaced it, hooked everything back up to cell and it fired up and was getting sufficient gas. That was all on Saturday and Sunday now I’m not getting anything again after flooding the engine on monday. A friend flooded it trying to start it because I have a Holley 650 spread bore, double pumper and when you push the accelerator it sprays some fuel! Anyway, after he flooded it he kept trying to start it so he poured some gas down the carburetor, and everytime he tried starting it he pumped the gas. So, after holding the pedal to the floor and cranking it, and taking out all the plugs and cranking it, then replacing the plugs, it still will not start! If I pour gas down the carb, it will run until that gas runs out, everytime it starts it sort of shakes and its smoking black out of the pipes. It still isn’t getting gas from the gas can or fuel cell even after a new mechanical fuel pump. I know this has been long and thank you for enduring. And advice at all?
the engine did have an electric pump in the tank but is also set up for a mechanical pump on the block and sorry I failed to mention that I had cleaned it out with injector cleaner.
As much money as I have spent on that carburetor I don’t believe I will be changing it anytime soon. I do have hedman headers, a cam, an aluminum intake, and its been bored over.

Answers for The Question

  1. Mr. Hypothetical
  2. Mad Jack
  3. Donkeyeyes
  4. Jeffbudda73