Too much carb?

I'll try to list as much about the motor as i know: 355 motor with 350 auto trans (with 2600 stall), mild to agressive cam (don't know specs), ported iron heads, weiand team g intake, solid rockers, full msd ignition, manual fuel pump, long tube headers.  Its all on a 71 nova. I had a holly 600 cfm carb on it and the motor seemed to need more fuel.  The motor would want to turn off while at stop signs, pulling into driveway or while in gear with my foot on the brake (after about 10 seconds or so).  Local engine guy advised me to upgrade to 750 cfm.  I bought and installed 750 cfm edelbrock performer(#1407).  I ran it out of the box and motor runs great with none of the issues i had before with the 600.  However, i noticed that the car doesn't respond like it used to whenever i accelerate aggressively. It takes about a second and then the car accelerates great. I assume i need to tune it but i'm hoping i didn't buy too much carb.  What do you guys recommend, that doesn't include replacing the carb....that would be a pain in the butt.  But any tips are welcomed though, thanks.  

almost sounds like the old card had a vac leak.
from what i have heard a 350 even with ported heads wouldnt need 750, a 650 would be plenty but i dnt think that is too awfull much. but i would think that the larger carb is causing your poor accel of the line. iv been told that the engine vac needs to be able to use the carburetor venturis to speed up the air that passes by it into the intake. if the venturis are to big the venturis
will not force the air to speed up through the carb as well as they do with a 600cfm.

i think you would be able to adjust it to where it accels better but i would take it to sombody that has alot of experiance with tuning carbs. mine is still kicking my ass

hope that helps.  

The carb you have is a little on the heavy side but should work fine with some adjustments. MAX CFM required for your motor assuming ported and polished runners with 90% eff, max RPM 6500 and bored .030 over (355ci)is about 610 cfm, The nice thing about the Edelbrock carbs (were carters) is that you can adjust the jetting with metering rods you get in a strip kit, so you, not the shop can tune the carb and then run it to see what the results are. You can google for a CFM calculator and punch in a varity of numbers to show where your carb should be, I run a Edelbrock 600 cfm elect choke on a performer rpm air gap intake, performer cam (510 lift)9.5 comp, edelbrock 2.02 heads on a 355ci in a 79 Z28, and it screams.....good luck.  

I would try a set of lighter springs on the metering rods.