Stalling Issue (Slant Six w/Holley 1920 Carburetor)

I hoping someone can help diagnose the possible cause of a stalling issue I'm having.

The car ('66 Barracuda) starts fine and the choke seems to step down and operate as it should while warming up. However, if I step hard on the accelerator pedal before the car is fully warmed up, the car will sputter and stall. It can be started again right away without any problem. If I ease into the accelerator, it will run just fine and not stall. Once the car is fully warmed up, this problem goes away.

I rebuilt the carburetor a few years ago in the hope this would fix it, but no such luck.

Any clues what might be wrong?

Thanks.