Edelbrock part #7594 RPM Air-Gap 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.