If it was almost anything but an edelbrock I'd say power valve.... but sadly the edelbrock doesn't use a power valve...
But that does simplify it a bit.
Check your choke, see that it is opening when warm. That black plastic round thing on your elect choke side has a bi metal spring inside of it. When the spring heats up it loads the choke plate shaft twisting the plate open. the spring travel can be adjusted by loostening the screws (usually 3 of them) that clamp the black plastic housing in place. You can loosten the 3 screws and dial the plastic "knob" clockwise or counter clockwise. It will say "lean-rich" on the knob telling you which way to turn it.
You might need to turn it in the lean direction to help the spring flip the plate open all the way.
But you'll want to test this with a hot spring and a cold spring, you don't want it would too tight in either direction. If you have it wound too lean then it won't choke fully or at all when it's cold and you need the choke closed.
If you know that your choke is working then I'd go after idle mixture screws next. those are the 2 adjustment screws on the front of the carb. Take a screwdriver and turn them all the way in making sure to count the number of turns for both screws. This way you can go back to where it was set in case this is not the issue.
Some carbs find the right idle fuel feed at 1 turn on each screw, some like as much as 5 full turns, there is no one set rule.
I'd take a stab at saying you might settle in at around 3 turns each but I wouldn't bet on it.
Count your turns on both screws to turn the screws in until they stop, write the number of turns down. Figure an average for both screws (left one is 4 turns, right one is 3, go 3.5)from all the way in (closed) turn them both out to your average number between the 2 and start there.
With the truck running start turning them in and listen for the idle to clean up and rpm to rise. Go half turn in on both, half turn at a time. Keep the adjustments even for the 2 screws. See if you can find a sweet spot.
Find your cleanest, highest RPM idle setting now with 1/4 turn adjustments on each screw, (fine tuning) find the sweet spot on a warm engine then go out from there a 1/4 turn on each screw and leave it.
Hint, if you can turn the screws in all the way and the engine still runs, then it's flooding inside and you need to go after float/needle/seat.
