Holden Commodore VB VK VL 304 5.0L EFI 308 EFI Heads Pacemaker Headers PH5600

Pacemaker PH5600 headers (extractors) are designed for Holden Commodore VB, VC, VH and VK fitted with a VN-VT 304 5.0L EFI Holden V8 engine or a 308 Holden V8 fitted with EFI cylinder heads.

Pacemaker also lists PH5600 as suitable for VL Commodore when fitted with a VN-VS steering rack.

PH5600 uses Pacemaker's Tri-Y design with 41mm (1⅝") primary pipes, 48mm (1⅞") secondary pipes and 57mm (2¼") outlets, providing a performance header specifically designed around early Commodore Holden EFI V8 conversions.

IMPORTANT – Will not fit with a manual steering K-frame. VL applications require a VN-VS steering rack.

Please check availability and current lead time before ordering.

Key Features

• Designed for early Commodore Holden EFI V8 conversions
• Tri-Y header design
• 41mm (1⅝") primary pipes
• 48mm (1⅞") secondary pipes
• 57mm (2¼") outlets
• Suits VN-VT 304 5.0L EFI Holden V8 engine conversions
• Suits 308 Holden V8 fitted with EFI cylinder heads
• Manual and automatic transmission applications
• Power steering compatible with the correct steering and K-frame configuration
• Air conditioning compatible
• Oxygen sensor provision

Construction

Pacemaker PH5600 uses a Tri-Y configuration with 41mm (1⅝") primary pipes feeding into 48mm (1⅞") secondary pipes and 57mm (2¼") outlets.

The standard headers are supplied in Pacemaker's distinctive protective blue finish.

Additional Options

Ceramic Coating: Ceramic coating may be available as an option for improved heat management and corrosion resistance. Please contact Best Mufflers for current availability.

DSF63: Pacemaker specifies DSF63 as the replacement exhaust manifold/header gasket for PH5600.

Vehicle Fitment

• Holden Commodore VB: 1978-1980 – EFI Holden V8 conversion
• Holden Commodore VC: 1980-1981 – EFI Holden V8 conversion
• Holden Commodore VH: 1981-1984 – EFI Holden V8 conversion
• Holden Commodore VK: 1984-1986 – EFI Holden V8 conversion
• Holden Commodore VL: 1986-1988 – conversion application with VN-VS steering rack
• Engine: VN-VT 304 5.0L EFI Holden V8
• Alternative Engine: 308 Holden V8 fitted with EFI cylinder heads
• Transmission: Manual / Automatic – see gearbox compatibility below
• Drive: Rear-Wheel Drive

Important: PH5600 is an engine-conversion header. The later 304 EFI engine was not the original factory engine in VB-VL Commodores, so engine position, steering, K-frame and transmission configuration must be checked before ordering.

Header Specifications

• Part Number: PH5600 L/R
• Brand: Pacemaker
• Design: Tri-Y
• Primary Pipe: 41mm (1⅝")
• Secondary Pipe: 48mm (1⅞")
• Outlet: 57mm (2¼")
• Power Steering: Yes
• Air Conditioning: Yes
• Oxygen Sensor Provision: Yes
• EGR: N/A
• Replacement Gasket: DSF63
• Approximate Fitting Time: 3 hours

Gearbox Compatibility

• Australian 4-speed with cable clutch
• Commodore VN-VS 5-speed
• Toyota Supra 5-speed with Hatfield bellhousing and crossmember
• Holden Trimatic
• Turbo 350 automatic
• Turbo 400 automatic
• Turbo 700 4-speed automatic
• Commodore Getrag 5-speed (VT gearbox)
• Ford Top Loader

Fitment Notes

VB-VK: Pacemaker's primary application is VB, VC, VH and VK Commodore fitted with a VN-VT 304 5.0L EFI engine or 308 with EFI cylinder heads.

VL Commodore: Pacemaker's current catalogue states PH5600 will fit VL with a VN-VS steering rack. VL fitment is therefore dependent on the steering conversion and should be confirmed before ordering.

Manual Steering K-Frame: PH5600 will not fit with a manual steering K-frame.

Power Steering: Pacemaker lists PH5600 as power-steering compatible when the appropriate K-frame and steering configuration is used.

Air Conditioning: Pacemaker lists PH5600 as air-conditioning compatible.

Engine Conversion: Engine mounts, K-frame, steering rack, starter motor, transmission, bellhousing and other conversion components can affect clearance.

Protect painted surfaces during trial fitting and check steering, starter motor, transmission, engine mount and exhaust clearances before final tightening.

What's Included

• Pacemaker PH5600 left-side header assembly
• Pacemaker PH5600 right-side header assembly

Do not assume header bolts, gaskets or other installation hardware are included unless specifically confirmed with the current kit before ordering.

Recommended With

• DSF63 exhaust manifold/header gaskets
• Suitable downstream exhaust connections to match the 57mm (2¼") header outlets

Why Good Headers & Exhaust Systems Matter

At 4,000 rpm, the 5.0L Holden V8 theoretically draws approximately 10,000 litres of intake air per minute at 100% volumetric efficiency and expels around 30,000 litres of hot exhaust gas per minute at approximately 600°C.

Actual airflow varies with engine specification, RPM, volumetric efficiency, camshaft, cylinder heads, induction system and engine tune.

A well-designed header and exhaust system helps manage this high gas flow efficiently, reducing restriction and improving exhaust scavenging, torque, throttle response and engine performance.

Installation Tips

PH5600 is an engine-conversion header, so confirm the complete engine, K-frame, steering rack and transmission configuration before installation.

VL applications require particular attention because Pacemaker specifies the use of a VN-VS steering rack.

Pacemaker lists an approximate fitting time of 3 hours. Actual installation time can vary depending on the vehicle and conversion components.

Professional installation is recommended.

Warranty & Compliance

Pacemaker headers are covered against manufacturing defects subject to Pacemaker's current warranty terms and conditions.

Because PH5600 is intended for an engine conversion, the completed vehicle must comply with applicable Australian state or territory requirements covering engine conversions, emissions, exhaust noise and vehicle modifications.

Any catalytic converters, oxygen sensors and emissions-control equipment required for the engine and vehicle must remain correctly installed and operational.

FAQ

What vehicles do PH5600 headers suit?
Pacemaker's primary application is Holden Commodore VB, VC, VH and VK fitted with a VN-VT 304 5.0L EFI Holden V8 or a 308 fitted with EFI cylinder heads. Pacemaker also lists VL fitment when a VN-VS steering rack is used.

What engine does PH5600 suit?
Pacemaker specifies the VN-VT 304 5.0L EFI Holden V8 or a 308 Holden V8 fitted with EFI cylinder heads.

Are PH5600 headers Tri-Y?
Yes. Pacemaker's current specification identifies PH5600 as a Tri-Y design.

What size are PH5600 headers?
They use 41mm (1⅝") primary pipes, 48mm (1⅞") secondary pipes and 57mm (2¼") outlets.

Will PH5600 fit a VK Commodore?
Yes. VK is specifically included in Pacemaker's current PH5600 application.

Will PH5600 fit a VL Commodore?
Pacemaker's current catalogue says PH5600 will fit VL with a VN-VS steering rack. The complete steering and K-frame configuration should be confirmed before ordering.

Will PH5600 fit a manual steering K-frame?
No. Pacemaker specifically states that PH5600 will not fit with a manual steering K-frame.

Will PH5600 fit with air conditioning?
Yes. Pacemaker lists PH5600 as air-conditioning compatible.

Does PH5600 have oxygen sensor provision?
Yes. Pacemaker lists oxygen sensor provision for PH5600.

What gasket suits PH5600?
Pacemaker specifies DSF63.

Can I pick up from the store?
Yes. Pick up is available but must be pre-arranged before collection.

How much is freight?
Freight varies depending on your delivery location and where stock is available. Please contact us for freight charges before ordering. Where possible, we can arrange dispatch from the nearest available product location to help reduce freight costs and delivery times.

Do you ship to the USA?
Yes. Best Mufflers regularly ships exhaust systems and exhaust parts to customers throughout the United States.

Please note that import duties, tariffs, taxes, and customs clearance fees are not included in the product or shipping price. Once your order is processed and the applicable charges are calculated, we will send you a secure payment link to finalise the import duties and tariff charges before dispatch.

Customer Support

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