dual carb setup

I purchased a 64 valiant v100 a while back. The 225 motor has been totally redone with .30 over and a mild cam. It has an offenhauser dual carb intake with two 1-barrels. The car has amazing torque and runs really well. Drove it to the Charlotte show this past weekend - did really well on the 400 mile roundtrip. My question involves the dual carbs - why is the single carb offenhauser preferred over the duals? I am really impressed with this car and was just curious as to why a single 2 or 4bbl would be preferred. My car has the original column mounted three speed.