Cylinder Head - E-CNC 355 Cylinder Head - E-CNC 355 Cylinder Head - Chamber Size 110cc - Rect. Port - Single - Bare - 2.30 in. Intake/1.88 in. Exhaust Valve - Chevy Big Block. Features: CNC Ported To Achieve Optimal Air Flow. For Maximum Horsepower And Torque. For High Performance Street/Light Duty Racing. High Quality Valve Springs. Modified To Increase Fuel Efficiency. And Maximum Power. Made In U.S.A.. For Pre-Pollution Controlled Vehicles Or Engine Swaps Or Race Use. When you design and sell the best-engineered performance products in the world, you have to have a rigorous testing program. Why? Without adequate testing, there's no way to stand behind your product with confidence. That's why every product we design and sell at Edelbrock is tested and approved by Edelbrock engineers in a real world environment on state-of-the-art equipment. Our three Super Flow computerized engine dynos are capable of measuring 11 separate engine variables up to speeds of 12,000 rpm. For 2007, we added a new Super Flow SF902 engine dyno. It's fully automated and programmable to simulate various driving situations, and is equipped with WinDyn software for the very latest in testing equipment. For real-world tuning, there's our Super Flow model SF-840 eddy-current chassis dyno that can handle up to 1,000 hp at the wheels and speeds of 200 mph. When all testing is completed, the results evaluated, and the part has passed all performance criteria, then, and only then, is the product deemed ready for production. These precise testing procedures are applied to the entire Edelbrock line for performance that's guaranteed. Edelbrock test vehicles are driven by Edelbrock engineers and employees to get a "real world" feeling for the performance improvements. Our products are also tested and used by professional race car teams and drivers. Working with these talented individuals is just another extension of our research and development process so when we say "proven performance" we really mean it! Top racing teams in all forms of motorsports rely on Edelbrock to produce parts that they can count on to win races and championships. Further underscoring our commitment to the racing community, Edelbrock is the only aftermarket intake manifold manufacturer licensed by NASCAR.