Pacemaker Headers PH12700 – Toyota LandCruiser HJ75, HZJ78, HZJ79 4.2L 1HZ Diesel (Non-EGR)

Pacemaker Headers PH12700 with PHB075 base pipe are engineered for the Toyota LandCruiser 70 Series 4.2L 1HZ diesel engine. Designed for vehicles not fitted with EGR, this system replaces the restrictive factory manifold to improve exhaust gas flow, reduce backpressure, and increase usable torque—especially beneficial for towing and off-road applications.

The 1HZ engine produces a large volume of exhaust gas under load. The tuned pipe sizing and smooth collector design of the PH12700 system improves scavenging efficiency, helping the engine breathe more freely and deliver smoother power across the rev range.

Key Features

• Mandrel-bent 42mm primary pipes, 51mm secondary pipes, 63mm outlet
• Tuned-length design for improved torque and drivability
• Smooth merge collectors for enhanced exhaust scavenging
• Direct-fit system with included base pipe

Construction

• High-quality steel tubing with precision welds
• Pacemaker Blue heat-resistant coating rated to approximately 800°C
• Built for durability in demanding off-road and towing conditions

Engine Airflow & Exhaust Design

At approximately 4000 rpm, the 4.2L 1HZ engine processes around 7,100 L/min of intake air and produces approximately 21,300 L/min of exhaust gas (based on ~85% volumetric efficiency and exhaust expansion at temperature). This large increase in exhaust gas volume highlights why properly designed extractors are critical to reducing backpressure and improving engine efficiency.

Additional Options

• Ceramic Coating (PHC70 / PHC90): Improved heat management and durability
• Header Gasket Set DSF082: high-quality replacement gasket for a reliable seal between the cylinder head & exhaust headers / manifold.

What’s Included

• PH12700F front header assembly
• PH12700R rear header assembly
• PHB075D base pipe
• Gaskets and bolts for header-to-pipe connection

Recommended With

• New manifold gasket (DSF082)
• Intermediate pipe or full exhaust system upgrade
• Heavy-duty exhaust mounts and hardware

Fitment Notes

• Suitable for Toyota LandCruiser HJ75, HZJ78, HZJ79 4.2L 1HZ
• Non-EGR models only
• For EGR-equipped vehicles, use PH12701
• Left-hand drive compatible
• Protect painted surfaces during installation
• Clearance may vary depending on engine mounts and modifications

Warranty & Compliance

• Backed by Pacemaker manufacturer 2-year warranty
• Verify emissions and registration compliance in your state

Frequently Asked Questions

Will this fit EGR models?
No, this version suits non-EGR vehicles only. Use PH12701 for EGR-equipped models.

Will this fit Left Hand Drive models?
Yes, these headers will fit LHD models. 

Do you send Internationally?
Yes, we send internationally. Import duties and tariffs may apply. Contact us before ordering

Is this good for towing and off-road use?
Yes, improved exhaust flow increases low-end torque, making it ideal for towing, touring and off-road conditions.

Do I need a new gasket?
A new gasket (DSF082) is recommended to ensure a proper seal and long-term reliability.

Does this improve performance?
Yes, by reducing backpressure and improving scavenging, these headers enhance throttle response and overall engine efficiency.

Customer Support

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