Not all of them are great carbs. I've found the 72 to 74 are the best. There are some later non-leanburn versions out there too. Many years ago I tried running a later 400 carb on my 360 fury. It was lean and just didn't make the power. I swapped to a 73 440 thermoquad and the difference was substantial. I think they're great but the plastic bodies are going bad on most of mine. They're just getting old.
