1984 Ford F150 300 six automatic

Hello, I have replaced the carb. fuel filter, fuel pump, distributer cap, rotor, plugs wires, new plugs, new fuel tank the truck runs great starts
on high idle when cold, warms up idles down when I kick It down, theirs no miss the trans shifts great until it shifts into third and I accelerate hard it falls on it’s face like all the fuel is shut off when I let up it’s like it catches up and runs fine until I accelerate it again the same thing. I have checked the choke to make sure it’s operating correctly when I accelerate (I tied it back with a wire tie) help would be greatly appreciated, Thanks