Ford Falcon XK XL XM XP 5.0L Windsor GT40P Pacemaker Headers PH4025

Pacemaker PH4025 headers (extractors) are designed for Ford Falcon XK, XL, XM and XP models converted to a 5.0L Windsor V8. Unlike a general-purpose Windsor header, PH4025 was developed around a specific early Falcon conversion configuration incorporating GT40P cylinder heads, column-change automatic transmission, C4 automatic and a high-torque starter with the starter solenoid positioned on top.

PH4025 features Pacemaker's TUNED design with 41mm (1⅝") primary pipes and 76mm (3") outlets. The header is designed to improve exhaust flow and scavenging, helping improve throttle response and engine performance in modified early Falcon Windsor V8 applications.

IMPORTANT – Use short-top spark plugs and short 90-degree spark plug leads to provide adequate clearance between the spark plugs, leads and header pipes.

Not sure which headers to use for your Windsor engine? Read our Ford Windsor header guide here.

Please check availability and current lead time before ordering.

Key Features

• Designed for Ford Falcon XK, XL, XM and XP 5.0L Windsor V8 conversions
• Developed specifically around GT40P cylinder heads
• Pacemaker TUNED design
• 41mm (1⅝") primary pipes
• 76mm (3") outlets
• Designed around a C4 automatic transmission and column-change configuration
• Designed around a high-torque starter with the solenoid positioned on top
• Pacemaker recommends short-top spark plugs and short 90-degree spark plug leads
• Designed to improve exhaust flow, throttle response and engine performance

Construction

Pacemaker PH4025 headers use mandrel-bent pipework and a vehicle-specific TUNED design developed for early Ford Falcon Windsor V8 conversions using GT40P cylinder heads.

The standard headers are supplied in Pacemaker's protective finish. Ceramic coating is also available separately for customers wanting additional heat management and surface protection.

Additional Options

• Ceramic Coating: Available separately – please contact us for current coating options, pricing and lead time
• DSF3: Recommended exhaust manifold/header gasket – available separately
• Matching exhaust system components – available separately

Vehicle Fitment

• Make: Ford
• Model: Falcon
• Series: XK / XL / XM / XP
• Model Years: 1960-1966
• Application: V8 Conversion
• Engine: 5.0L Windsor V8
• Cylinder Heads: GT40P
• Transmission: Automatic

Header Specifications

• Part Number: PH4025L/R
• Design: TUNED
• Primary Pipe: 41mm (1⅝")
• Secondary Pipe: N/A
• Outlet: 76mm (3")
• Power Steering: N/A
• Air Conditioning: N/A
• Oxygen Sensor: N/A
• EGR: N/A
• Recommended Gasket: DSF3
• Approximate Fitting Time: 3 hours

Fitment Notes

• Designed for Ford Falcon XK-XP models converted to a 5.0L Windsor V8.
• Pacemaker specifically developed PH4025 around GT40P cylinder heads.
• Automatic transmission application.
• Designed around a C4 automatic and column-change configuration.
• Designed around a high-torque starter with the solenoid positioned on top of the starter.
• Short-top spark plugs and short 90-degree spark plug leads are recommended to provide clearance to the header pipes.
• Confirm the engine mounts, crossmember, steering, transmission and starter arrangement before ordering where the vehicle has been modified from the configuration used to develop these headers.
• Protect painted or ceramic-coated surfaces during trial fitting and installation.
• Check clearance around the starter motor, steering, engine mounts, transmission, spark plugs, plug leads and surrounding components before fully tightening the headers.
• Professional installation is recommended.

What's Included

• Pacemaker PH4025L left-hand header assembly
• Pacemaker PH4025R right-hand header assembly

Gaskets, bolts, outlet flanges and other installation hardware should not be assumed included unless specifically confirmed with the current PH4025 package supplied.

Recommended With

• DSF3: Exhaust manifold/header gaskets
• Short-top spark plugs
• Short 90-degree spark plug leads
• Suitable downstream exhaust connections to match the header outlets

Why Good Headers & Exhaust Systems Matter

At 4,000 rpm, a 5.0L Windsor 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 RPM, engine load, volumetric efficiency, camshaft specification and engine condition. These figures are theoretical values intended to illustrate the substantial volume of gas that must pass through the exhaust system at higher engine speeds.

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

• Confirm the vehicle uses the appropriate engine, cylinder-head, transmission, starter and steering configuration before installation.
• Apply penetrating lubricant to existing exhaust fasteners before removal.
• Remove all traces of the old manifold gaskets and inspect the cylinder-head sealing surfaces.
• Fit new DSF3 exhaust manifold/header gaskets.
• Use the recommended short-top spark plugs and short 90-degree spark plug leads.
• Trial-fit both header assemblies and carefully check spark-plug and plug-lead clearance.
• Check clearance around the starter motor, steering, engine mounts, transmission and surrounding components.
• Protect painted or ceramic-coated surfaces during trial fitting and installation.
• Check all exhaust connections for leaks after installation.
• Inspect header mounting hardware after the initial heat cycles.

Warranty & Compliance

Pacemaker PH4025 headers are covered against manufacturing defects subject to Pacemaker's current warranty terms and conditions.

As PH4025 is intended for a modified early Falcon V8 conversion, the completed vehicle and exhaust installation must comply with applicable state or territory requirements covering engine conversions, exhaust modifications, vehicle noise and roadworthiness.

FAQ

Which Ford Falcons do PH4025 headers suit?
Pacemaker PH4025 headers are designed for Ford Falcon XK, XL, XM and XP models converted to a 5.0L Windsor V8.

Are PH4025 headers designed for GT40P cylinder heads?
Yes. Pacemaker specifically states that PH4025 was designed to fit GT40P cylinder heads.

What size are the PH4025 header pipes?
PH4025 uses 41mm (1⅝") primary pipes and 76mm (3") outlets.

What transmission does PH4025 suit?
Pacemaker currently specifies PH4025 as an automatic transmission application. The headers were developed using a C4 automatic with column change.

Do PH4025 headers require special spark plugs or leads?
Pacemaker recommends using short-top spark plugs and short 90-degree spark plug leads to provide adequate clearance between the plugs, leads and header pipes.

Does starter motor position matter?
Yes. PH4025 was developed using a high-torque starter with the solenoid positioned on top of the starter. The starter configuration should be checked before ordering.

Will PH4025 fit a 289 or 347 Windsor?
Pacemaker's current application specifically lists PH4025 for a 5.0L Windsor V8 conversion. Fitment to other Windsor capacities should not be assumed solely because they share the Windsor engine family. Please contact us with your engine, cylinder heads, mounts, transmission and vehicle configuration before ordering.

Which header gaskets are recommended?
Pacemaker currently specifies DSF3 for PH4025.

Can PH4025 headers be ceramic coated?
Yes. Ceramic coating is available as an optional upgrade. Please contact us for current coating options, pricing and lead time.

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.

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