Holden VN 308 304 EFI Air Gap Dual Plane Intake Manifold Cast

Holden VN 308/304 EFI Air Gap Dual Plane Intake Manifold (Natural Cast Finish)

Unlock efficient, spreading air-fuel delivery for carburettted Holden V8 powerplants with this Air Gap Dual Plane intake. Specifically engineered for Holden VN and later heads, it’s a robust, natural-cast solution designed to optimize throttle response and mid-range power across a broad RPM band from 1500 to 6500 RPM. This manifold is non-EGR and features a square-bore carburettor pad to accommodate modern aftermarket carburettors with both manual and electric choke options.

Compatibility & Fitment

• Fits Holden 304 V8 engines (will not suit early Holden 308 cylinder heads).
• Designed for late model Holden VN engine models with EFI; not compatible with VT engines that have factory roller cams.
• Intended for carburettor setups using a square-bore pad; not compatible with factory OEM fuel rails (requires Aeroflow Fuel Rail Kit AF6999-4003).
• For non-EFI applications, use A6010-4000.

Key Features

• Air Gap, dual-plane design to promote even air-fuel distribution and improved throttle response across the RPM range.
• Carburettor mounting pad supports aftermarket square-bore carburettors with both manual and electric choke options.
• Natural cast finish with substantial compatibility for late-head configurations, water necks, air conditioning, and HEI ignition systems in most builds.
• Designed to maintain steady air-fuel flow for maximum performance and efficiency in carburetted setups.

Technical Specifications

• RPM range: 1500–6500 RPM (as specified for broad performance across the usable range).
• Overall height from carb pad to bottom: 150 mm (check bonnet clearance).
• Port size: 1.20" x 2.05".
• Square bore carburettor pad; non-EGR design.
• Intake manifold gasket: 5REGIM-308VN.
• Carburettor studs: 5/16-18" (x4).
• Throttle bracket mounting hole: 5/16-18" (x1).
• Ports: two 3/8" NPT ports (with one steel port plug included) and three 1/2" NPT ports (with two steel port plugs included).
• Fuel rails and plumbing: AF6999-4003 includes 2 x Fuel Rails (-8ORB) and -8AN crossover line with fittings.
• Hardware: 6 x mounting brackets, 6 x M6 socket cap screws (25mm UHL), 6 x M6 hex screws (10mm UHL), 4 x M6 nuts.
• Fuel system note: This manifold does not work with factory OEM fuel rails; requires Aeroflow Fuel Rail Kit AF6999-4003.
• Injectors: Requires 14mm short injectors (33.60mm length) (sold separately).

What’s Included

• 2 x Fuel rails (-8ORB) with Aeroflow connector kit
• -8AN crossover braided line (100 series) with two 90° non-full-flow taper fittings
• 3 x -8AN to -8ORB fittings
• 1 x -8ORB hex port plug
• 6 x mounting brackets
• 6 x M6 socket cap screws (25 mm UHL)
• 6 x M6 hex screws (10 mm UHL)
• 4 x M6 nuts
• Intake manifold gasket (5REGIM-308VN)

Installation & Tuning Notes

• Intake runners should be port-matched to your cylinder heads for optimal performance.
• Ensure bonnet clearance before installation due to the 150 mm overall height.
• Designed to work with aftermarket square-bore carburettors; verify choke type (manual or electric) for compatibility.
• Not compatible with VT factory roller camshaft configurations; use appropriate non-EFI or EFI-specific variants as noted.
• Plan for EFI-to-carburettor rail requirements: this intake requires the Aeroflow Rail Kit AF6999-4003 for proper fuel delivery.

Performance & Use Cases

Ideal for carburetted Holden 304 V8 builds aiming for broad, responsive power across idle to mid-range RPM. The Air Gap design helps minimize heat soak, maintains consistent air temperature at the runners, and provides improved throttle response in high-performance street applications and light to moderate race setups. The natural cast finish adds a classic look while withstanding the vibrations and heat of daily use.

Compatibility Summary

Best for: Holden VN-era 304 V8 EFI engines with late-model heads. Not suitable for early 308 cylinder heads or VT-era engines with factory roller cams. For non-EFI engines, choose the A6010-4000 variant. This manifold uses aftermarket fuel rails (AF6999-4003) and 14 mm short injectors (sold separately) for proper fuel delivery.