Carburetor on 72 Charger with a 318

I need to replace my carburetor on my 72 Charger SE, automatic, with a 318.
She currently has a 2 barrel Carter AFB which we tried to have rebuilt. The mechanic said it had been modified and is leaking fuel. Since the carburetor was rebuilt the car sputters and the carb puts out puffs of smoke and leaks fuel. We are considering replacing with a Street 500 cfm 2-bbl Carburetor Holley 2300 Series. Is this an appropriate replacement for my engine? Will it fit or require an adapter plate? If it requires an adapter plate, which one? Is there a better option for a 2 barrel carburetor. I'm new at this and my mechanic isn't a Mopar expert so any help/ suggestions will be greatly appreciated.:o
Author: Charlie72