{"id":7289,"date":"2026-06-20T05:44:53","date_gmt":"2026-06-20T05:44:53","guid":{"rendered":"http:\/\/australianholden.com\/?p=7289"},"modified":"2026-06-22T10:50:03","modified_gmt":"2026-06-22T10:50:03","slug":"hk-ht-hg-holden-radiator-upgrade-guide","status":"publish","type":"post","link":"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/hk-ht-hg-holden-radiator-upgrade-guide\/","title":{"rendered":"HK, HT, HG Holden Radiator Upgrade Guide"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\"><\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The HK, HT and HG Holden range holds a special place in Australian automotive history. Built between 1968 and 1971, these cars introduced the Red Motor six-cylinder family, the iconic Monaro coupe line, and the arrival of Holden\u2019s early V8 performance engines. They were engineered for Australian roads and conditions, and when new, the cooling systems were more than capable of handling daily driving.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Fast forward more than fifty years, and things look very different.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Today, overheating is one of the most common issues faced by HK\u2013HT\u2013HG owners. Even cars with mechanically sound engines often struggle in traffic, on hot days, or during long highway runs. The factory radiator design simply wasn\u2019t built for modern traffic congestion, aged internal corrosion, or the demands of modified engines.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That\u2019s where radiator upgrades come in.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Why Upgrade the Factory Radiator?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The original copper-brass radiator fitted to HK\u2013HT\u2013HG Holdens was strong for its time, but it now faces several limitations.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Common Issues with Original Radiators<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Internal rust and scale buildup<\/li>\n\n\n\n<li>Reduced coolant flow<\/li>\n\n\n\n<li>Blocked cooling tubes<\/li>\n\n\n\n<li>Age-related joint fatigue<\/li>\n\n\n\n<li>Poor efficiency in traffic conditions<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Even a \u201cclean\u201d original radiator can be internally restricted without visible signs.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Symptoms of a Failing Radiator<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Before upgrading, it\u2019s important to confirm the radiator is actually the problem.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Key Symptoms<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Rising temperature in traffic<\/li>\n\n\n\n<li>Normal temperature at speed, overheating when stopped<\/li>\n\n\n\n<li>Coolant discoloration (rusty or muddy appearance)<\/li>\n\n\n\n<li>Cold spots across radiator surface<\/li>\n\n\n\n<li>Frequent coolant loss or overflow<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A simple temperature check across the radiator core can quickly reveal flow issues.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Best Direct Replacement Option<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Recommended Product: Re-Cored Copper-Brass Radiator<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Benefits<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Maintains factory appearance<\/li>\n\n\n\n<li>Fully rebuildable design<\/li>\n\n\n\n<li>Suitable for restorations<\/li>\n\n\n\n<li>OEM-style fitment<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Best For<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Concours restorations<\/li>\n\n\n\n<li>Original vehicles<\/li>\n\n\n\n<li>Period-correct builds<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A professional re-core can restore original cooling performance if done properly.<\/p>\n\n\n<div id=\"fu_ebay_0\"><!-- Presentation: cols = 4, rows = 2, slideshow = Manual, slides = 3, slideId = 0 --><div class=\"fu_ebay_results_container \">\n<h5 class=\"fu_ebay_results_title\" style=\"display: block !important;\">\n<a name=\"fu_slidetop_0\"><\/a><a href=\"https:\/\/www.ebay.com.au\/?mkcid=1&#038;mkrid=705-53470-19255-0&#038;siteid=15&#038;campid=5339152561&#038;customid=5339151688&#038;toolid=10049&#038;mkevt=1\" class=\"fu_ebay\" style=\"display:inline !important;\" rel=\"nofollow\" target=\"_blank\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/australianholden.com\/wp-content\/plugins\/fast-ebay-listings\/US\/Right_Now_108x45.gif?resize=108%2C45&#038;ssl=1\" style=\"border:0;display:block !important;\" width=\"108\" height=\"45\" alt=\"Right Now on eBay\"\/><\/a>&nbsp;HK HT HG Radiator<\/h5>\nLoading&#8230;<\/div>\n<\/div>\n<script>\n<!--\nvar content_fu_ebay_0 = null;\nvar waitForDepends_fu_ebay_0 = setInterval(function () {\n  if (typeof jQuery !== \"undefined\") {\n  if (window.fu_is_bot_useragent !== undefined) {\n    clearInterval(waitForDepends_fu_ebay_0);\n    if (typeof jQuery.ajax == \"undefined\") {\n      console.log(\"Fast eBay Listings: jQuery.ajax missing. Are you using jQuery.Slim that doesn't include ajax? \");\n      return;\n    }\n    if (fu_is_bot_useragent) return;\n    content_fu_ebay_0 = jQuery(\"#fu_ebay_0\");\n    jQuery(document).ready(jQuery.ajax({\n      type : \"post\",\n      url : \"https:\/\/australianholden.com\/wp-admin\/admin-ajax.php\",\n      data : {\n        action : \"fu_ebay_load_search\",\nfuDisableAPICache : 0,\nfuTraceLogging : 0,\nebay_country : \"AU\",\nfu_ebay_customId : \"\",\nfu_ebay_widget : 0,\nfu_ebay_picwidth : 225,\nfu_ebay_arrangement : 0,\nfu_ebay_title : \"HK HT HG Radiator\",\nfu_ebay_query : \"HK HT HG Holden radiator\",\nfu_ebay_searchInDesc : 0,\nfu_ebay_searchLocation : \"Internationally\",\nfu_ebay_pickupPostcode : \"\",\nfu_ebay_pickupRadius : 0,\nfu_ebay_sort : \"BestMatch\",\nfu_ebay_categoryIds : \"6030\",\nfu_ebay_sellers : \"\",\nfu_ebay_sellerType : \"\",\nfu_ebay_buyingOptions : \"\",\nfu_ebay_conditionOptions : \"\",\nfu_ebay_minPrice : 0,\nfu_ebay_maxPrice : 0,\nfu_ebay_minBids : 0,\nfu_ebay_maxBids : 0,\nfu_cols : 4,\nfu_rows : 2,\nfu_slideshow : \"Manual\",\nfu_slides : 3,\nfu_slideId : 0,\n\n      },\n      success : function( response ) {\n        content_fu_ebay_0.html( response );\n      },\n      error: function(e) {\n        console.log(\"Fast eBay Listings: deferred loading error: \" + e);\n      }\n    }));\n  }}\n}, 10);\n\/\/-->\n<\/script>\n\n\n\n<h1 class=\"wp-block-heading\">Best Overall Upgrade<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Recommended Product: Aluminium Performance Radiator<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Benefits<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Improved heat dissipation<\/li>\n\n\n\n<li>Larger cooling capacity<\/li>\n\n\n\n<li>Lighter than factory unit<\/li>\n\n\n\n<li>More efficient in stop-start traffic<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Best For<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Touring vehicles<\/li>\n\n\n\n<li>Modified engines<\/li>\n\n\n\n<li>Hot climate driving<\/li>\n\n\n\n<li>Daily-driven classics<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Aluminium radiators are the most popular modern upgrade for classic Holdens.<\/p>\n\n\n<div id=\"fu_ebay_1\"><!-- Presentation: cols = 4, rows = 2, slideshow = Manual, slides = 3, slideId = 1 --><div class=\"fu_ebay_results_container \">\n<h5 class=\"fu_ebay_results_title\" style=\"display: block !important;\">\n<a name=\"fu_slidetop_1\"><\/a><a href=\"https:\/\/www.ebay.com.au\/?mkcid=1&#038;mkrid=705-53470-19255-0&#038;siteid=15&#038;campid=5339152561&#038;customid=5339151688&#038;toolid=10049&#038;mkevt=1\" class=\"fu_ebay\" style=\"display:inline !important;\" rel=\"nofollow\" target=\"_blank\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/australianholden.com\/wp-content\/plugins\/fast-ebay-listings\/US\/Right_Now_108x45.gif?resize=108%2C45&#038;ssl=1\" style=\"border:0;display:block !important;\" width=\"108\" height=\"45\" alt=\"Right Now on eBay\"\/><\/a>&nbsp;HK HT HG Holden aluminium radiator<\/h5>\nLoading&#8230;<\/div>\n<\/div>\n<script>\n<!--\nvar content_fu_ebay_1 = null;\nvar waitForDepends_fu_ebay_1 = setInterval(function () {\n  if (typeof jQuery !== \"undefined\") {\n  if (window.fu_is_bot_useragent !== undefined) {\n    clearInterval(waitForDepends_fu_ebay_1);\n    if (typeof jQuery.ajax == \"undefined\") {\n      console.log(\"Fast eBay Listings: jQuery.ajax missing. Are you using jQuery.Slim that doesn't include ajax? \");\n      return;\n    }\n    if (fu_is_bot_useragent) return;\n    content_fu_ebay_1 = jQuery(\"#fu_ebay_1\");\n    jQuery(document).ready(jQuery.ajax({\n      type : \"post\",\n      url : \"https:\/\/australianholden.com\/wp-admin\/admin-ajax.php\",\n      data : {\n        action : \"fu_ebay_load_search\",\nfuDisableAPICache : 0,\nfuTraceLogging : 0,\nebay_country : \"AU\",\nfu_ebay_customId : \"\",\nfu_ebay_widget : 0,\nfu_ebay_picwidth : 225,\nfu_ebay_arrangement : 0,\nfu_ebay_title : \"HK HT HG Holden aluminium radiator\",\nfu_ebay_query : \"HK HT HG Holden aluminium radiator\",\nfu_ebay_searchInDesc : 0,\nfu_ebay_searchLocation : \"Internationally\",\nfu_ebay_pickupPostcode : \"\",\nfu_ebay_pickupRadius : 0,\nfu_ebay_sort : \"BestMatch\",\nfu_ebay_categoryIds : \"6030\",\nfu_ebay_sellers : \"\",\nfu_ebay_sellerType : \"\",\nfu_ebay_buyingOptions : \"\",\nfu_ebay_conditionOptions : \"\",\nfu_ebay_minPrice : 0,\nfu_ebay_maxPrice : 0,\nfu_ebay_minBids : 0,\nfu_ebay_maxBids : 0,\nfu_cols : 4,\nfu_rows : 2,\nfu_slideshow : \"Manual\",\nfu_slides : 3,\nfu_slideId : 1,\n\n      },\n      success : function( response ) {\n        content_fu_ebay_1.html( response );\n      },\n      error: function(e) {\n        console.log(\"Fast eBay Listings: deferred loading error: \" + e);\n      }\n    }));\n  }}\n}, 10);\n\/\/-->\n<\/script>\n\n\n\n<h1 class=\"wp-block-heading\">Single Core vs Multi-Core Radiators<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Radiator construction plays a major role in cooling efficiency.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Single Core<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Closest to factory feel<\/li>\n\n\n\n<li>Adequate for stock engines<\/li>\n\n\n\n<li>Lower cost option<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Multi-Core (Twin or Triple Core)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Greater cooling capacity<\/li>\n\n\n\n<li>Better heat rejection<\/li>\n\n\n\n<li>Ideal for V8 conversions or modified Red Motors<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For most street-driven HK\u2013HT\u2013HG Holdens, a quality twin or triple-core aluminium radiator provides the best balance.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Cooling Fan Compatibility<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">A radiator upgrade is most effective when paired with proper airflow management.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Common Issues<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Weak airflow at idle<\/li>\n\n\n\n<li>Overheating in traffic<\/li>\n\n\n\n<li>Inefficient factory fan setups<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Even a high-quality radiator will struggle without adequate airflow.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Best Cooling Fan Upgrade<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Recommended Product: Davies Craig Thermatic Electric Fan Kit<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Benefits<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Improved airflow at idle<\/li>\n\n\n\n<li>Reduced engine load<\/li>\n\n\n\n<li>Better temperature control in traffic<\/li>\n\n\n\n<li>Adjustable activation settings<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Best For<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Modified vehicles<\/li>\n\n\n\n<li>Touring setups<\/li>\n\n\n\n<li>Hot weather driving<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Electric fans are one of the most effective supporting upgrades for radiator performance.<\/p>\n\n\n<div id=\"fu_ebay_2\"><!-- Presentation: cols = 4, rows = 2, slideshow = Manual, slides = 3, slideId = 2 --><div class=\"fu_ebay_results_container \">\n<h5 class=\"fu_ebay_results_title\" style=\"display: block !important;\">\n<a name=\"fu_slidetop_2\"><\/a><a href=\"https:\/\/www.ebay.com.au\/?mkcid=1&#038;mkrid=705-53470-19255-0&#038;siteid=15&#038;campid=5339152561&#038;customid=5339151688&#038;toolid=10049&#038;mkevt=1\" class=\"fu_ebay\" style=\"display:inline !important;\" rel=\"nofollow\" target=\"_blank\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/australianholden.com\/wp-content\/plugins\/fast-ebay-listings\/US\/Right_Now_108x45.gif?resize=108%2C45&#038;ssl=1\" style=\"border:0;display:block !important;\" width=\"108\" height=\"45\" alt=\"Right Now on eBay\"\/><\/a>&nbsp;Davies Craig electric fan kit<\/h5>\nLoading&#8230;<\/div>\n<\/div>\n<script>\n<!--\nvar content_fu_ebay_2 = null;\nvar waitForDepends_fu_ebay_2 = setInterval(function () {\n  if (typeof jQuery !== \"undefined\") {\n  if (window.fu_is_bot_useragent !== undefined) {\n    clearInterval(waitForDepends_fu_ebay_2);\n    if (typeof jQuery.ajax == \"undefined\") {\n      console.log(\"Fast eBay Listings: jQuery.ajax missing. Are you using jQuery.Slim that doesn't include ajax? \");\n      return;\n    }\n    if (fu_is_bot_useragent) return;\n    content_fu_ebay_2 = jQuery(\"#fu_ebay_2\");\n    jQuery(document).ready(jQuery.ajax({\n      type : \"post\",\n      url : \"https:\/\/australianholden.com\/wp-admin\/admin-ajax.php\",\n      data : {\n        action : \"fu_ebay_load_search\",\nfuDisableAPICache : 0,\nfuTraceLogging : 0,\nebay_country : \"AU\",\nfu_ebay_customId : \"\",\nfu_ebay_widget : 0,\nfu_ebay_picwidth : 225,\nfu_ebay_arrangement : 0,\nfu_ebay_title : \"Davies Craig electric fan kit\",\nfu_ebay_query : \"Davies Craig electric fan kit\",\nfu_ebay_searchInDesc : 0,\nfu_ebay_searchLocation : \"Internationally\",\nfu_ebay_pickupPostcode : \"\",\nfu_ebay_pickupRadius : 0,\nfu_ebay_sort : \"BestMatch\",\nfu_ebay_categoryIds : \"6030\",\nfu_ebay_sellers : \"\",\nfu_ebay_sellerType : \"\",\nfu_ebay_buyingOptions : \"\",\nfu_ebay_conditionOptions : \"\",\nfu_ebay_minPrice : 0,\nfu_ebay_maxPrice : 0,\nfu_ebay_minBids : 0,\nfu_ebay_maxBids : 0,\nfu_cols : 4,\nfu_rows : 2,\nfu_slideshow : \"Manual\",\nfu_slides : 3,\nfu_slideId : 2,\n\n      },\n      success : function( response ) {\n        content_fu_ebay_2.html( response );\n      },\n      error: function(e) {\n        console.log(\"Fast eBay Listings: deferred loading error: \" + e);\n      }\n    }));\n  }}\n}, 10);\n\/\/-->\n<\/script>\n\n\n\n<h1 class=\"wp-block-heading\">Water Pump Condition Matters<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">A radiator upgrade alone will not solve cooling issues if the water pump is weak.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Symptoms of a Worn Pump<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Coolant leaks from pump housing<\/li>\n\n\n\n<li>Bearing noise<\/li>\n\n\n\n<li>Poor circulation<\/li>\n\n\n\n<li>Overheating under load<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A healthy water pump is essential for radiator efficiency.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Best Water Pump Upgrade<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Recommended Product: Dayco Water Pump<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Benefits<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Reliable coolant circulation<\/li>\n\n\n\n<li>Strong bearing construction<\/li>\n\n\n\n<li>Direct replacement fitment<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Best For<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Engine rebuilds<\/li>\n\n\n\n<li>Cooling system upgrades<\/li>\n\n\n\n<li>Preventative maintenance<\/li>\n<\/ul>\n\n\n<div id=\"fu_ebay_3\"><!-- Presentation: cols = 4, rows = 2, slideshow = Manual, slides = 3, slideId = 3 --><div class=\"fu_ebay_results_container \">\n<h5 class=\"fu_ebay_results_title\" style=\"display: block !important;\">\n<a name=\"fu_slidetop_3\"><\/a><a href=\"https:\/\/www.ebay.com.au\/?mkcid=1&#038;mkrid=705-53470-19255-0&#038;siteid=15&#038;campid=5339152561&#038;customid=5339151688&#038;toolid=10049&#038;mkevt=1\" class=\"fu_ebay\" style=\"display:inline !important;\" rel=\"nofollow\" target=\"_blank\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/australianholden.com\/wp-content\/plugins\/fast-ebay-listings\/US\/Right_Now_108x45.gif?resize=108%2C45&#038;ssl=1\" style=\"border:0;display:block !important;\" width=\"108\" height=\"45\" alt=\"Right Now on eBay\"\/><\/a>&nbsp;Dayco HK HT HG Holden water pump<\/h5>\nLoading&#8230;<\/div>\n<\/div>\n<script>\n<!--\nvar content_fu_ebay_3 = null;\nvar waitForDepends_fu_ebay_3 = setInterval(function () {\n  if (typeof jQuery !== \"undefined\") {\n  if (window.fu_is_bot_useragent !== undefined) {\n    clearInterval(waitForDepends_fu_ebay_3);\n    if (typeof jQuery.ajax == \"undefined\") {\n      console.log(\"Fast eBay Listings: jQuery.ajax missing. 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Radiator upgrades are one of the most effective improvements available for restoring reliability and preventing overheating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Whether you choose a re-cored factory radiator for originality or a modern aluminium unit for performance, the key is ensuring the entire system works together. Water pump condition, thermostat operation, airflow and coolant quality all play an equal role in keeping temperatures under control.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For most owners, a properly executed radiator upgrade transforms the car from an anxious summer driver into a dependable classic capable of long-distance touring with confidence.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Related Articles<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/hk-ht-hg-holden-cooling-system-problems\/\" type=\"post\" id=\"7287\">HK HT HG Holden Cooling System Problems<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/holden-186-engine-issues-explained\/\" type=\"post\" id=\"7268\">Holden 186 Engine Issues Explained<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/hr-holden-radiator-upgrade-guide\/\" type=\"post\" id=\"7272\">HR Radiator Upgrade Guide<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/hr-holden-cooling-system-problems\/\" type=\"post\" id=\"7270\">HR Holden Cooling System Problems<\/a><\/li>\n\n\n\n<li>Best Coolants for Classic Holdens<\/li>\n\n\n\n<li><a href=\"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/hr-holden-transmission-problems\/\" type=\"post\" id=\"7274\">HR Holden Transmission Problems<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/hr-holden-rust-problems\/\" type=\"post\" id=\"7266\">HR Holden Rust Problems<\/a><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The HK, HT and HG Holden range holds a special place in Australian automotive history. Built between 1968 and 1971, these cars introduced the Red Motor six-cylinder family, the iconic Monaro coupe line, and the arrival of Holden\u2019s early V8 performance engines. They were engineered for Australian roads and conditions, and when new, the cooling [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":577,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1],"tags":[],"class_list":["post-7289","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>HK, HT, HG Holden Radiator Upgrade Guide - Australian Holden<\/title>\n<meta name=\"description\" content=\"They were engineered for Australian roads and conditions, and when new, the cooling systems were more than capable of handling daily driving.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/australianholden.com\/index.php\/2026\/06\/20\/hk-ht-hg-holden-radiator-upgrade-guide\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"HK, HT, HG Holden Radiator Upgrade Guide - Australian Holden\" \/>\n<meta property=\"og:description\" content=\"They were engineered for Australian roads and conditions, and when new, the cooling systems were more than capable of handling daily driving.\" \/>\n<meta property=\"og:url\" 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