Hello, I'm Danny.
There is a strong possibility that the fuel pressure regulator is stuck open causing a rich condition that is giving you the black smoke-rough running condition from extremely high fuel pressure. The fuel pressure regulator is located within the in-tank electric fuel pump assembly. Here is a tutorial showing how to check fuel pressure. The fuel pressure specification for your truck is with key on-engine off is 55-62 PSI.
Here is a tutorial showing how to replace an in-tank fuel pump:
I've attached picture steps below showing how to remove and replace the fuel pump on your truck. Hope this helps and thanks for using 2CarPros.
Images (Click to enlarge)
Thursday, February 4th, 2021 AT 8:54 PM