Edelbrock part #1128 Ford Flatheads for 1938-48 Ford/Mercury, 24 Stud cylinder heads feature the original Edelbrock script logo design for Fords and Mercury's, and are casted at the Edelbrock Foundry in the USA of T-6 tempered A356 aluminum. These Flatheads are rugged, ribbed internally and externally, with a large water capacity and excellent breathing characteristics. This High Lift/Large Chamber version feature a new "raised roof" combustion chamber design that is CNC machined for high lift cams and is perfect for reducing compression in supercharger applications or on low octane fuel. These Edelbrock High Lift heads have increased valve clearance and increased flow capacity.