Pacemaker PH5250 Headers – Holden HK HT HG 253 / 308 V8

Pacemaker PH5250 headers are engineered for Holden HK, HT, and HG vehicles running 253 or 308 V8 engines. Designed for street and performance use, these competition headers improve exhaust scavenging, boost mid-range torque, and enhance performance. Precision mandrel-bent tubing ensures smooth flow, while the heavy-duty flanges and Pacemaker Blue finish guarantee long-lasting durability.

Key Specifications

• Part Number: PH5250
• Design: Interference design for competition street performance
• Primary Pipes: 1.75"
• Secondary Pipes: 1.78"
• Outlet Size: 3.00" four-bolt flanged
• Material: Mandrel-bent steel with precision TIG welding
• Finish: Pacemaker Blue heat-resistant coating (rated to 800°C)

Performance Insight

At 4000 rpm, the 308ci Holden V8 engine draws approximately 10,000 L/min of intake air and expels around 30,000 L/min of exhaust gas. The tuned-length design of PH5250 headers optimises this flow, improving exhaust pulse scavenging, reducing back pressure, and boosting usable torque and power across the rev range.

Fitment Notes

• Fits Holden HK, HT, and HG – 253 & 308 Holden V8 engines
• Will fit Turbo 350 transmissions
• Will not fit Powerglide
• Compatible with hydraulic clutch conversions
• Gasket – see product code DSF009A
• Ceramic Coating available – see PHC10

Installation Tips

To prevent scratches during installation, wrap headers in cling wrap before fitting. Once positioned, trim around the flange and start bolts. Remove the remaining wrap before tightening. Lubricate fasteners with WD40 or similar for easier assembly and future removal.

Recommended With

• Gaskets – see DSF009A
• Ceramic Coating – see PHC10
• Intermediate pipes or collector adaptors (sold separately)

Customer Support

For orders, technical advice, or fitment help:

📞 Call Now: +61 2 9547 3511 ✉️ Email Us

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87A Planthurst Road, Carlton NSW 2218, Australia
Exhaust Systems Since 1983