It looks like the truck had factory air? Are you also getting rid of the air conditioner portion? It looks like you have the plenum still inside the cab.
If you're getting rid of all the heat/ac function, then the plenum and ductwork under/in the dash can come out as well. The vents in the dash can be removed and the trim plate for a heater only truck can be installed on the dash pad. The instrument cluster bezel from a heater only truck could replace the factory air bezel.
BTW, your excess parts could help someone installing or refurbishing a factory air system.