Every Edelbrock Cylinder Head is MADE IN USA for quality and performance! Cast and heat treated at the Edelbrock Foundry and machined at Edelbrock’s manufacturing facility in the USA, Edelbrock heads are the best in quality and performance. Using highly efficient ports and state-of-the-art combustion chamber shapes, Edelbrock cylinder heads offer improved performance throughout the rpm range for great throttle response and top-end horsepower. Top-quality features include threaded inserts in rocker stud and exhaust bolt holes for superior strength and durability, and manganese-bronze valve guides. These are features that some other companies don’t include!