engine dead spot

[sbc10guy]

Hi guys, ive been messing with my 327 lately and it has a dead spot as soon as you hit the throttle.It runs great at higher rpm when you hit the gas but the throttle response is terrible and it hesitates and spits and sputters when you hit the gas hard at a dead stop. If i drive it normal it runs fine but as soon as you hammer on it it hesitates and runs bad. The motor is a 327 thats bored .30, has a .464/.480 crane cam, 202 camel hump heads 487 casting, hydraulic lifters harland sharp roller rockers, victor jr. edelbrock intake, and holley 650 double pumper carb. I dont know if its the mix of parts thats wrong, ive messed with the timing and made it better but i cant get it right. Any advice is greatly appreciated. Thanks.