I have built a few 6-pack engines over the years and they are great. Tuning the carbs is not any harder than tuning a 4-barrel vacuum holley, when you know how it is done. I like to use a new set of carbs because you are not starting out with something that is wore out or had many WRONG mods done to them. Here is my last engine I built. I think nothing looks meaner than three carbs on an engine, unless it has a belt turning it.