Advance Headers | Mild Steel High Performance Tri-Y Extractors | Holden Commodore VTII-VZ LS1 LS2 5.7L 6.0L | A317X

PRODUCT CONTENTS:

• 1 x Heavy-Duty Mild Steel High-Performance Left-Hand Tri-Y Header Assembly
• 1 x Heavy-Duty Mild Steel High-Performance Right-Hand Tri-Y Header Assembly

Key Features:

• Advanced High-Performance Tri-Y (4-2-1) configuration steps gas flow columns through specialized pairings to optimize exhaust scavenging velocity and torque punch
• Heavy-wall, mandrel-bent 1¾" primary pipelines transition smoothly into massive 2" secondary runners to eliminate backpressure restrictions entirely
• Substantially optimizes low-to-mid range torque delivery and throttle response—ideal for rapid street acceleration, heavy towing configurations, and dyno-tuned setups
• Heavy-duty mild steel construction structurally built to handle intense thermal expansion cycles and extreme under-hood operating heat cycles safely
• Thick, precision laser-cut cylinder head flanges maintain a flat, ultra-stable mating footprint to permanently guard against warping and high-pressure gas leaks

Specifications:

⚠️ Crucial Generation-Specific Compliance & Harness Warnings:
Due to the oversized primary and secondary runner paths shifting the downstream outlet boundaries, the following fitment requirements must be adhered to:
1. VZ Models Catalytic Converter Relocation: On all VZ series variants (both 5.7L and 6.0L), the factory catalytic converters must be physically cut, rotated, and re-positioned downstream to align correctly with the modified exit geometry of these high-performance collectors.
2. 6.0-Litre V8 Sensor Wire Extension: When retrofitting this kit onto 6.0-Litre LS2/L76/L98 engine variations, you MUST utilize 2 x Rear Oxygen Sensor Wiring Extensions (Part No. OSER) to bridge the factory loom safely down to the altered sensor bungs without stretching or damaging harness lines.
3. Engine Limitation Note: Mapped exclusively for aluminum GM Gen III/IV block structures. Will not align with early VT Series I iron-block Holden 5.0L/304 engines.

Please Note: Due to the custom catalytic adjustments and sensor extensions required on later model profiles, professional installation by an exhaust specialist or a qualified performance workshop is highly recommended to guarantee proper alignment and a perfect leak-free seal.