Edelbrock Intake Manifold RPM Air Gap Vn Holden 1988-1998 EFIEdelbrock part #75945 RPM Air Gap EFI intake manifold is designed for street and high performance 308 383 c. i. d. Holden V8 engines that utilize the 1988 98 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.