I know that one reason is that Clevelands have a canted valve design, which until fairly recently meant an "unfair" advantage. The Cleveland is not an inline valve head and even the small 2 barrel head has large valves. This begs the question--why are twisted wedge heads legal? They have large valves, rotated combustion chamber. The twisted wedges even have modern port designs. Technically, the twisted wedges should not be legal. You might try using this as ammuntion in favor of allowing Clevelands. Besides, any advantage the Cleveland heads had over other smallblock heads are long gone. Example: Edelbrock Victor heads. These babies flow right up there with the Yates heads.
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