Small-ish engine for the size of carb, they're more responsive to throttle opening than downleg boosters. Stick cars are wicked sensitive to tip in.
I previously had a 360 with magnum heads and a 600 VS holley and it had quite literally the same exact issues. My friend's demon has that same carb on his 71 Demon with an auto and it masks it a lot. It's still not what I'd consider good.
I have some serious doubts about you being able to crank your car at 40F and 80% humidity and then just put it in gear within 10 seconds and have it run perfect, no stumbles, no revving, no nothing. Otherwise it's got to be very stock.