Carb problems

So I recently rebuilt a 318 into a 328, and I used the same intake that was already on it, except I took off a 1" spacer that was on the intake, and I'm not sure if it is this or something else but I'm having a problem that I didn't have before the build. When I start the car to warm it up I am not able to drive it for 15-20 minutes, because when I try and take off or kick it down to early the car dies, sounds like it gets flooded but I'm not sure because it starts right back up and drives fine, Im using a carter carb on it, its a pretty stock motor, mild cam and everything is rebuilt(with exception of the carb).

Is this a carb problem or something else, any thoughts and/or ideas would be great.

Thank you

Dakoda