HELP!!!!!!

I just finished my engine, got it in the car, and it purrs like a kitten, at idle. Under load (i.e. driving, normal) it will jump and lurch and stall. I can feel it backfiring in the pedal, and hear it. What can be wrong? Everything in the engine is brand new or remanned to be brand new. I am running the stock computer, and a q-junk. Please help me out. I am waiting to get another carburator so i can ditch the computer controlled garbage (I already have the intake and maifold).

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1984 z-28
fresh 327 stroker
350 cam
edelbrock intake, and carb
accel distributor
beefed up T-5
posi rear
edelbrock air filter
flowmaster exhaust
exhaust cut out right before the cat

ps The edelbrock carb turned out to be to much. So, I have a stocker on it right now.