Truck is an 84' 351w with an Edelbrock 1406 carb on it.
Was on my way home from school yesterday, got about two blocks from my house, and felt like I was losing power as I got to a stop sign after being on the highway. Truck stalled out... had to floor the pedal to get it to fire over, and saw a nice black cloud shoot out of the pipes- so obviously it got very rich.

Limped it home, got in my driveway and let it idle... again it died out. Pulled off the air cleaner and took a look into the carb. Even with the engine off (mechanical fuel pump) fuel was dripping in from the secondaries, and the back half of the carb was full of fuel. Eventually the gas even started seeping through where the carb is mounted to the manifold. I was just on the highway and passing, so I did have it WOT and open the secondaries.

So for some reason the secondaries were still receiving fuel even though they were not being operated. I snapped the throttle a few times, moved all of the linkage multiple times, hit it all with carb cleaner, and the fuel stopped dripping in. Got it started again, and could still see black smoke when I burped the throttle but the carb was still probably full of fuel... took it out around the neighborhood and opened it up, and again the same thing started happening.
I can manage to get it running OK if I jab the gas a few times. As long as I don't hit WOT and make the secondaries operate, it'll run completely fine.

***Does anybody have any idea what could cause the secondaries to continue to dump fuel even after they're closed and even with the engine off? I'm not sure if they're vacuum or mechanical- I think mechanical? (Edelbrock 1406 carb)

 

It was doing again the night of the day that it happened... it sat all day yesterday without being started. Drove to work today like a grandpop in order to not open the secondarys and risk flooding out and being late to work, and I was on E so couldn't risk wasting any fuel with it flooding either.
After work I got gas and decided to giver hell and see what happens. For just about the whole ride home I was peddle to the floor seeing if it would act up again, and it didn't. Maybe something was just binding up, or a little dirty? No clue, but i'll keep playing with it to see if it'll reoccur

 

Well the problem is back! Drove home from work with no hint of a problem. Got a call that a buddy needed a pull... and it wouldn't start without the foot to the floor, and a nice huge blast of black smoke. Thought maybe it was a fluke so tried slapping the peddle, driving it like a mad man, poking around at the levers on the carb... nothing worked at all this time. For the whole night it would just flood itself out, which is not fun when you're in the middle of the woods at night.
If anybody has any idea at all, I would really appreciate it. I really just can't figure it out at all