{"product_id":"advance-headers-holden-6-cylinder-hd-hg-a84","title":"Advance Headers | Mild Steel Exhaust Extractors | Holden HD-HG Red Motor Powerglide Auto | A84","description":"\u003ch2\u003eAdvance Headers High-Performance Mild Steel Exhaust Extractors for Holden HD to HG Red Motor Engines (Specially Formed for Powerglide Automatics)\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eThe Advance Headers Performance Exhaust Extractors (A84) are heavy-duty classic tubular manifolds purpose-built for golden-era Australian Holden passenger cars and commercial utility platforms. Engineered specifically to solve the notoriously tight clearance conflicts within HD, HR, HK, HT, and HG engine bays running iconic Holden inline 6-cylinder \"Red Motor\" configurations, this custom-profiled assembly is manufactured from high-grade mild steel to ensure ultimate structural reliability. By dropping heavy exhaust backpressure, it optimizes gas scavenging velocity to unlock vital low-to-mid range torque, crisp throttle response, and that timeless classic Aussie inline-6 rumble.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv class=\"feature-block\"\u003e\n\u003cdiv class=\"feature-content pb-6\"\u003e\n\u003ch3 style=\"color: #e60000; font-weight: bold;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003ePRODUCT CONTENTS:\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Heavy-Duty Mild Steel Red Motor Performance Extractor Header Assembly\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eKey Features:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSpecially configured and clearance-mapped around the wide physical dimensions of the vintage GM 2-speed Powerglide automatic transmission casing to prevent linkage binding\u003c\/li\u003e\n\u003cli\u003eTuned mandrel-bent primary piping pathways ensure completely uniform internal flow geometry, optimizing exhaust velocity and eliminating heavy factory log manifold restrictions\u003c\/li\u003e\n\u003cli\u003eSubstantially optimizes low-to-mid range torque bands—ideal for street cruising responsiveness, crisp acceleration, and classic restorations\u003c\/li\u003e\n\u003cli\u003eHeavy-duty mild steel construction structurally built to handle intense under-bonnet thermal expansion cycles and typical classic inline-6 vibrations safely\u003c\/li\u003e\n\u003cli\u003eThick, precision laser-cut cylinder head flanges maintain a flat, ultra-stable mating footprint to permanently guard against warping, face distortion, and high-pressure exhaust leaks\u003c\/li\u003e\n\u003cli\u003eEngineered for a fast workshop turnaround, featuring an estimated baseline installation window of just 1.5 hours\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eSpecifications:\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cdiv class=\"specs\"\u003e\n\u003cul class=\"flex flex-col space-y-2 text-xs\"\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003eBrand:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003eAdvance Headers\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003ePart Number:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003eA84\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003eMaterial:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003eMild Steel (Standard Finish)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003eEngine Suitability:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003eHolden 6-Cylinder \"Red Motor\" Petrol Engines Only (149ci, 161ci, 179ci, 186ci Blocks)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003eTransmission Compatibility:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003eOptimized for 2-Speed Powerglide Automatic Configurations\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003eComponent Type:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003ePerformance Exhaust Extractors \/ Headers\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003eEstimated Fitting Time:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003e1.5 Hours\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"text-gray-500 font-semibold mr-1\"\u003eWelding Required:\u003c\/span\u003e \u003cspan class=\"text-gray-700\"\u003eNo (Direct Bolt-On Configuration to Cylinder Head Face)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003e⚠️ Crucial Drivetrain Geometry \u0026amp; Cylinder Head Architecture Alignment Warnings:\u003c\/strong\u003e\u003cbr\u003e1. \u003cstrong\u003eStrict Engine Style Mapping:\u003c\/strong\u003e This product (Part No. \u003cstrong\u003eA84\u003c\/strong\u003e) is shaped explicitly for traditional 9-port Holden Red inline-6 blocks. It \u003cstrong\u003ewill NOT fit later Blue or Black engines\u003c\/strong\u003e featuring 12-port cylinder heads due to entirely distinct exhaust port spacings and intake manifold mating configurations.\u003cbr\u003e2. \u003cstrong\u003eChassis Steering Column Clearance:\u003c\/strong\u003e Formed to sweep around original steering column pathways smoothly across the HD-HG platform run. Always check secondary bracket offsets if custom conversion linkages have been installed.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003ePlease Note: Professional installation by a classic vehicle exhaust specialist or restoration workshop is highly recommended to ensure proper starter motor access, underbody pipe paths, and a perfect leak-free seal.\u003c\/em\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch2\u003eImportant Information\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eThe image shown may not reflect the actual product design.\u003c\/li\u003e\n\u003cli\u003eEnsure your vehicle details match the application guide below before purchasing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv style=\"font-family: Arial, sans-serif; max-width: 100%; padding: 20px; border: 1px solid #ccc; border-radius: 5px; font-size: 1rem;\" class=\"product-details-container\"\u003e\n\u003ch2\u003eVehicle Applications for A84 Performance Red Motor Powerglide Extractors\u003c\/h2\u003e\n\u003cdiv style=\"width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch; margin-bottom: 10px;\"\u003e\n\u003ctable style=\"min-width: 1100px; border-collapse: collapse; font-size: 1rem; line-height: 1.5; width: 100%;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #f0f0f0; border-bottom: 3px solid #333;\"\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd; white-space: nowrap;\"\u003eMake\u003c\/th\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd; white-space: nowrap;\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd; white-space: nowrap;\"\u003eYear Range Spec\u003c\/th\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd;\"\u003eBody Type\u003c\/th\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd;\"\u003eChassis Series\u003c\/th\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd;\"\u003eEngine Details\u003c\/th\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd; white-space: nowrap;\"\u003eFitting Time\u003c\/th\u003e\n\u003cth style=\"padding: 10px 8px; text-align: left; border: 1px solid #ddd;\"\u003eDrivetrain \/ Fitment Notes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd; white-space: nowrap; font-weight: bold;\"\u003eHolden\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd; white-space: nowrap; font-weight: bold;\"\u003eStandard \/ Special \/ Premier \/ Kingswood \/ Monaro \/ Belmont\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd; white-space: nowrap;\"\u003e1965 – 1971\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e4-Door Sedan \/ 5-Door Station Wagon \/ Utility (Ute) \/ Panel Van \/ 2-Door Coupe\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eHD \/ HR \/ HK \/ HT \/ HG Series\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003e6-Cylinder Petrol Red Motor (149, 161, 179, 186 SOHC Blocks Only)\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd; white-space: nowrap;\"\u003e1.5 Hours\u003c\/td\u003e\n\u003ctd style=\"padding: 8px; border: 1px solid #ddd;\"\u003eRWD | Mandrel-bent upgrade layout custom clearance-mapped past classic transmission selector lines, oil cooling loops, and subframe crossmembers safely. Specifically optimized for Powerglide models.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch2\u003ePayment \u0026amp; Security\u003c\/h2\u003e\n\u003cp\u003eYour payment information is processed securely. We do not store credit card details nor have access to your credit card information.\u003c\/p\u003e","brand":"Advance Headers","offers":[{"title":"Default Title","offer_id":45735853719714,"sku":"A84","price":525.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0576\/1112\/4898\/files\/GenericHeader_faa4c47d-6893-4d18-8eed-f9324e9a3c42.png?v=1766995041","url":"https:\/\/nationaltowbars.com.au\/products\/advance-headers-holden-6-cylinder-hd-hg-a84","provider":"National Towbars Australia","version":"1.0","type":"link"}