Edelbrock Cylinder Head BBC Pro-Port Victor High Port Conventional Dr-17 Hip Pro-Port RawThe Edelbrock 615469 Big Block Chevy DR 17 Pro Port Cylinder head is designed specifically for the professional cylinder head porter and engine builder. Like the other Edelbrock Cylinder head, The Pro Port cylinder head is also cast in the USA at the state of the art Edelbrock Foundry with extra thick walls to allow for custom CNC porting. In most cases, seats and manganese bronze valve guides are included, but not installed. Please note: This head