I did read what you wrote, but then also said: (Below) This is the confusion. If a single is ok to run standard, why can't you run two? What is the purpose other than some carbs are too long to fit inline? Holley's 660s 4224 carbs were specifically designed for tunnel rams, wouldn't they have made them differently or designed them to mount sideways? It was my understanding it was just the physical size that dictated it.