For years I praised the AFB and is derivatives. However, When I installed a 1406 on my 273 I had problems. After messing with it for several weeks, I retuned it and bought a Street Demon. Problems solved!
I have never had issues with the AFB / Eldebrock style carbs, they just work.
I really like the Street Demons, just put a new one on my Duster. They are a set and forget about it carb.