The Man-A-Fre is an awesome setup. It's a performer too and very "streetable". While all 4 carbs have idle circuits, they are also connected by passages in the casting that help equalize and smooth-out the idle. The carbs are not totally-isolated from each other.

While a modern single 4bbl setup may perform better, it doesn't hold a candle to the "coolness" factor of a Man-A-Fre 4x2.

The ultimate and most sought-after classic hot rod induction setup.