Motor dies when gas pedal pressed

OK, this is a 318 2bbl 1974 Duster that I just bought. It is hard to start and wants to stumble and stall right off idle. I can't even touch the accelerator until it is well warmed up. I have to use a spray of starter fluid to start it. I temporarily wiredd the choke open to be able to run it. The previous owner put a brand new carb (2bbl) on it. Once it warms up, if I ease it through the flat spot when running in neutral, the engine will finaly rev up fine, but it is real difficult to get it to 2,000 where it will take any throttle to speak of. It's almsot like there is no accelerator pump in this carburetor. I'm starting to think there is dirt in the carb, what do you guys think? Fuel pump? Blocked fuel line?
DickJ