Designed for high rpm or large displacement competition 351 Windsor Ford V8s with a deck height of 9.5" which are used in drag racing or oval track engines operating between 4500 and 8500 rpm. This intake can be used with ported factory cast iron heads, however aftermarket aluminum heads are recommended, such as Edelbrock Victor Jr. heads 350-77169, Victor heads 350-77219 or equivalent for ultra high-horsepower. Runners have a 3.20 square-inch cross sectional area.