Holden HQ HJ HX WB 427 454 Big Block Chev Exhaust Headers [EXT291]
$995.45
Tax excluded
EXT291Performance headers (extractors) for Holden HQ, HJ , HX, HZ, WB, fitted with big block Chev engines. Featuring competition tuned length design mandrel-bent 51mm primary pipes, with 76mm flanged outlets that will improve exhaust flow, torque, and throttle response. Built from high-quality steel with thick flanges and a high temperature heat-resistant finish, these headers ensure an excellent, leak-free fit. Ideal for restorations, street performance, and weekend cruising. Click the image for larger views and more photos.
EXT291 Performance Headers – Holden (HQ, HJ, HX, HZ, WB)
EXT291 Performance headers (extractors) are a great performance upgrade designed for Holden 396 to 496 Big Block Chev engines, fitting HQ, HJ, HX, HX, and WB models. These tuned length design competition headers improve exhaust flow, increase performance, mid range torque, sharpen throttle response, and deliver a stronger exhaust note. Perfect for restorations, street performance, and weekend cruisers, they ensure a great fit with proven performance header quality.
Key Features
- Made to Order [3-4 weeks]
- Competition Headers
- Tuned length design
- Mandrel-bent 51mm primary pipes with 76mm outlets
- Thick, machined flanges for durability and reliable sealing
- Smooth merge collectors for improved scavenging and power delivery
Construction
- High-quality steel tubing with strong welds for long service life
- Painted with heat-resistant paint rated to 800°C
Additional Options
- Ceramic Coating (CC10): Enhanced durability and heat management
- Gaskets (DSF075): Available separately for optimal sealing
- Header Bolts [BOLO3-10] Available separately
Fitment Notes
- Will fit with Air-Conditioning
- Fits with original 350 engine mount spacers fitted on correct side. (RH spacer is 1¾"] [LH spacer is 1¼"]
- Will fit turbo 350 & turbo 400 automatic
- Protect painted surfaces and wrap headers during trial fitting
- Clearance may vary with engine mounts, steering, and aftermarket parts
- Collectors can be cut back slightly and re-flanged for 90mm outlets.
What’s Included
- Performance Headers EXT291-L left header assembly
- Performance Headers EXT291-R right header assembly
- Additional flanges to fabricate ] to exhaust system [2]
Recommended With
- New exhaust gaskets and sealant
- Header Bolts [16 required] See product code BOL03-10
- Matching intermediate pipes, joiners, or adaptors may be available (sold separately)
Warranty & Compliance
- Backed by 2 years manufacturer warranty
Customer Support
For phone orders, advice, or part enquiries – contact us:
EXT291
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EXT291Performance headers (extractors) for Holden HQ, HJ , HX, HZ, WB, fitted with big block Chev engines. Featuring competition tuned length design mandrel-bent 51mm primary pipes, with 76mm flanged outlets that will improve exhaust flow, torque, and throttle response. Built from high-quality steel with thick flanges and a high temperature heat-resistant finish, these headers ensure an excellent, leak-free fit. Ideal for restorations, street performance, and weekend cruising. Click the image for larger views and more photos.