Intake Manifolds Performer RPM Air-Gap, 1988-1998 For Holden, Commodore V8, VN Heads 253, 304, 308 SPELAB Spelab RPM Air-Gap intake manifold is designed for street and high performance 308-383 c.i.d. Holden V8 engines that utilize the 1988-1998 Holden VN cylinder heads. This RPM Air-Gap manifold is a dual-plane design that is tuned for both excellent throttle response and greater horsepower from 1500 to 6500 rpm. This manifold has been designed to fit both stock 1988-1998 EFI style heads and the Edelbrock Holden VN RPM cylinder heads. Brand: SPELAB Part Type: Intake Manifolds Intake Section Included: Complete Engine Block Deck Height: Standard deck Carburetor Quantity: One Intake Style: Dual plane Basic Operating RPM Range: 1,500-6,500 Intake Manifold Height: 5.820 in. Intake Color: Natural Intake Material: Aluminum EGR: No Quantity: Sold individually. Notes: This manifold has been designed to fit both stock 1988-1998 EFI style heads and the SPELAB Holden VN RPM cylinder heads. Special Attention: Manifold height: A-4.80 in., B-5.82 in.; Carb pad height: 5.31 in. Port exit dimensions: 1.16 in. x 2.00 in. FAQ Q1: What engines and vehicles is the SPELAB Intake Manifold Performer RPM Air-Gap compatible with?A1: The SPELAB Intake Manifold Performer RPM Air-Gap is specifically designed for 1988-1998 Holden Commodore V8 engines, particularly those using VN heads (253, 304, 308). It supports 308-383 c.i.d. displacement engines and is compatible with both 1988-1998 EFI-style heads and SPELAB Holden VN RPM performance cylinder heads. Q2: What is the "Air-Gap" design, and how does it improve engine performance?A2: The Air-Gap design creates an air gap between the intake manifold base and the engine, allowing cooler air to enter the intake. This helps lower intake temperatures and increase air density, which improves combustion efficiency and boosts power output. Particularly in the 1500-6500 RPM range, this design provides quicker throttle response and more horsepower, enhancing overall engine performance. Q3: What types of fuel systems is this intake manifold compatible with?A3: The SPELAB RPM Air-Gap intake manifold is designed to work with a single 4-barrel carburetor (square-bore style). It is compatible with both EFI and carbureted systems, making it ideal for performance builds that require an upgrade to support higher horsepower without sacrificing throttle response. Q4: Are any additional components or accessories needed for installing this intake manifold?A4: The SPELAB Intake Manifold Performer RPM Air-Gap comes as a complete intake section and typically requires standard tools for installation, such as wrenches and screwdrivers. It does not include gaskets, so you’ll need to purchase them separately. If you're upgrading to SPELAB Holden VN RPM cylinder heads, additional gaskets or components may be required for optimal fitment and sealing. Q5: What is the optimal RPM range for this intake manifold?A5: The SPELAB Intake Manifold Performer RPM...