Edelbrock #50459 E-Street cylinder 290 Oval Port head FOR Big-Block applications. The Edelbrock #50459 E-Street cylinder 290 Oval Port head is designed for Big-Block applications. The Edelbrock E-Street cylinder head offers American made quality and affordable performance. E-Street cylinder head features as-cast ports and are designed for entry-level street performance applications operating in the idle-to-5500 rpm range. The modern combustion chamber designs improve the combustion process and larger than stock intake and exhaust ports move more air through your engine for improve efficiency. For use on pre-pollution controlled vehicles only. Exhaust 45 deg/Intake 45 deg. Match with Edelbrock head gasket sets. Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4 reach with flat gasket seat. Designed for entry-level street performance engines and ideal for operating in the idle to 5500 rpm range. Includes hardened spring cups and Heli-Coil® threaded inserts in the rocker stud bosses for increased strength; these are the details that most low-cost competitors leave out of their heads. (Suggested) 0.4375 in. Valve Spring Maximum Lift. Instant response to any inquiries. If you are not sure this is the correct item for your car, you can send us VIN number of your vehicle, and we will check it for you! If you have any questions about this item, please ask. DEFECT/DELAY If there is any defect or delay? Items should be installed by authorised mechanics. Other destinations might have different tariffs or additional extended area cost. If You live outside Europe? If You have received damaged or faulty goods? United Kingdom, Italy, Germany, Latvia.