Running great one day and next it stalls every time I hit the gas too hard

1974 Dodge Dart Swinger with a fresh 360 LA, Holley 750DP, Edlebrock intake, stock ignition.

So on Saturday, I went for a boot on the back roads and had a great time doing burnouts at every intersection. The car was responsive and doing exactly what I wanted it to. I had a blast.

On Sunday my son comes over and I say lets go have some fun. First set of lights there's a new Mustang Shelby right in front of us. He's giving the look so I know it's on. Mopar vs. Ford. At the green I punched it, knowing he was going to and I kept up for the first couple of hundred feet, then he really hit and left us. Oh well, we continued out to the back roads for some more fun. First intersection, hit the gas and whump it stalled. From then on the rest of the drive, anytime you get aggressive with the gas pedal it stalls, even a highway speed it has a huge stumble if you hit the gas.

So my friends, where should I go with this. The vacuum is good, choke is manual and wide open, plugs are a little black for my liking, but I haven't really done anything except set the timing to 14 degrees at idle and 32 degrees all in. I haven't touched the carb, it came from my cousins 340 Dart he said he's never rebuilt it. Could something in the accelerator pump shot be dumping too much gas all of a sudden?