Designed for high rpm or large displacement competition 351 Windsor Ford with a deck height of 9.5" which are used in drag racing or oval track engines operating between 4500 and 8500 rpm. Super Victor # ED2924 can be used with ported factory cast iron heads, however aftermarket aluminium heads are recommended, such as Edelbrock Victor Jr. # ED77169 or Victor heads # ED77219 for ultra high-horsepower. Runners have a 3.20 square-inch cross sectional area. Made in USA