1976 chev fuel issue ?

[c10 custom]

Hey everybody i am having a fuel issue with a 1976 chev truck 454
I replaced the fuel pump already. Here is the story truck had not run in a long time so i got it running and i let it idle for about 20 minutes then shut it off. Then the next time i went to start it run really bad and was puffing black smoke and then i shut it off. so now i have no fuel coming up into the carburetor. I checked the fuel selector valve underneath and i can blow through the passages with a air gun all of them and i can hear the solenoid click when i move the switch back and forth on the dash. Not sure what to do next ?
any help would be great. Thank you