Olive Branch, MS – Edelbrock is excited to announce the release of its newest E-Street Cylinder Heads for Cathedral port GM LS3 engines (PN 77621). These cylinder heads are designed with Inconel exhaust valves, making them a premium replacement option for engine builds that require enhanced exhaust valve materials, such as those in marine applications or engines using power adders. These heads are identical to Edelbrock’s existing E-Street 77620 cylinder heads but are specifically tailored for applications with elevated exhaust temperatures with the significant addition of Inconel exhaust valves. Inconel, known for its high-temperature resistance, makes these heads perfect for boosted or nitrous-injected builds and marine applications, where water-cooled exhaust systems are often used, requiring superior exhaust valve performance. The architecture mirrors factory LS3 heads with a stock GM 15° valve angle, 69cc combustion chamber, and 260cc intake port volume. However, with a 2.165” x 1.590” valve job, these E-Street LS Cylinder Heads are premium, bolt-on-ready components designed to fit any high-performance or stock GM LS engine, providing seamless compatibility with all stock components. Sold in pairs, they come fully assembled with COMP Cams valve train components, including beehive valve springs, Chromoly-steel retainers, heavy-duty stainless-steel intake valves, and Inconel exhaust valves. The beehive valve springs support up to .570” lift camshafts and can accommodate lift up to .660”, making them ideal for a wide range of camshaft grinds, from mild to aggressive, especially in marine and power-adder applications. E-Street cylinder heads are made from premium 110 BHN aluminum alloy, machined to the industry’s highest standards, and inspected and assembled in San Jacinto, CA by Edelbrock’s expert technicians, ensuring top-tier quality and reliability. Each head features manganese-bronze valve guides for long-lasting durability. Special emphasis is placed on maintaining precise tolerances for valve seat concentricity, which guarantees a secure valve seal, eliminating leak-down and boosting cylinder pressures during engine operation. Additionally, the heads feature a unique dual spark plug pocket design, allowing for the use of either factory-style tapered seat spark plugs or gasketed seat plugs. This versatility provides users with wider heat range options, maximizing tuning flexibility. Edelbrock’s patented Clean Cast Technology ensures that all cylinder heads are free from casting flaws and have a smoother internal surface, which enhances both air and coolant flow. This technology improves power output and cooling capacity straight out of the box. The Edelbrock E-Street LS3 Cylinder Heads with Inconel exhaust valves are a perfect choice for any high-performance or stock replacement application with elevated exhaust temperatures and offer an excellent performance value for aftermarket GM LS cathedral port heads. For more information on the Edelbrock E-Street Cylinder Heads for GM LS3 Engines, visit www.edelbrock.com. Press Release Type: Product Company: Edelbrock Booth #: 22443 Show Categories: Racing & Performance Media Contact Name: Trent Goodwin Media Contact Email: tgoodwin@edelbrock.com Media Contact Phone: 9013753491 Photo Gallery: 102821