{"product_id":"improved-racing-ls-billet-rear-passage-plug-gm-gen-iii-iv-barbell-cnc-6061-t6-dual-o-ring-seal","title":"Improved Racing LS Billet Rear Passage Plug — GM Gen III\/IV Barbell, CNC 6061-T6, Dual O-Ring Seal","description":"\u003cp\u003e\u003cstrong\u003eImproved Racing's billet rear passage plug is a direct-fit replacement for the plastic GM barbell plug on Gen III \u0026amp; IV LS engines, engineered to stop unfiltered oil bypass and restore correct oil routing.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eOlder or factory plastic rear passage plugs in GM LS-series engines can deform, crack, or allow oil to bypass the filter. This billet aluminum oil diverter — commonly called a \"barbell\" plug — replaces the OEM plastic plug with a precision-machined part that seals the gallery and channels oil through the filter housing as intended. It’s a compact upgrade that addresses oil-flow integrity without modifying the engine block or oiling system.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this plug prevent dirty oil from bypassing the filter?\u003c\/h3\u003e\n\u003cp\u003eThe Improved Racing plug uses a dual O-ring sealing arrangement and a precisely machined profile to close off the rear oil passage. That positive seal blocks the route that allows unfiltered oil to shortcut past the filter media, keeping contaminants in the filter where they belong.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDouble O-ring design for two-stage sealing\u003c\/li\u003e\n  \u003cli\u003eAccurate internal geometry to guide oil through the filter housing\u003c\/li\u003e\n  \u003cli\u003eReplaces failure-prone plastic OEM barbells\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIs this a straight swap for GM Gen III \u0026amp; IV LS engines?\u003c\/h3\u003e\n\u003cp\u003eYes — the part is made to match the OEM dimensions and function so it installs in place of the factory plastic barbell plug. No block machining or adapter is required; installation uses the existing gallery opening and threads for a clean, direct fit.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect replacement for GM LS Gen III and IV rear barbell plug\u003c\/li\u003e\n  \u003cli\u003eM4x0.7 threaded removal hole for easy extraction if needed\u003c\/li\u003e\n  \u003cli\u003eForm-fit to factory gallery to maintain original oil routing\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat materials and manufacturing processes are used?\u003c\/h3\u003e\n\u003cp\u003eThe plug is CNC-machined from 6061-T6 aluminum for strength, dimensional accuracy, and corrosion resistance. Viton O-rings provide durable sealing against hot engine oil, and the part is manufactured domestically to consistent quality standards.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePrecision CNC-machined from billet 6061-T6 aluminum\u003c\/li\u003e\n  \u003cli\u003eViton O-rings for long-lasting oil resistance\u003c\/li\u003e\n  \u003cli\u003eMade in the USA for traceable manufacturing quality\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I remove or service the plug if it’s stuck?\u003c\/h3\u003e\n\u003cp\u003eThe plug includes a small threaded M4x0.7 port designed specifically to help removal. You can install a suitable extraction tool or screw to back the plug out without damaging the block, reducing the risk of seized or broken OEM plastic pieces.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eM4x0.7 threaded hole accepts removal tool or bolt\u003c\/li\u003e\n  \u003cli\u003eBillet construction resists distortion during extraction attempts\u003c\/li\u003e\n  \u003cli\u003eReduces chance of leaving broken plastic in the oil gallery\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Owners and builders of GM LS Gen III and IV engines who want a reliable, long-lasting replacement for the fragile OEM plastic rear barbell plug. It’s ideal for performance builds, routine maintenance upgrades, and any application where preserving proper oil circulation and filtering is a priority. If you value durable materials, positive sealing, and a simple direct-swap installation, this billet oil diverter plug is a practical upgrade.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will this replace the plastic barbell on my LS3\/LS7?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. It is a direct-fit replacement for GM LS Gen III \u0026amp; IV plastic barbell plugs, designed to match OEM gallery dimensions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What seals are used to prevent oil bypass?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: The plug uses two Viton O-rings for a positive, oil-resistant seal that prevents unfiltered oil from bypassing the filter.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Improved Racing","offers":[{"title":"Default Title","offer_id":48086587932830,"sku":"B08RF2YNYF","price":49.85,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/improved-racing-billet-barbell-front-profile.jpg?v=1785901166","url":"https:\/\/northtrailauto.ca\/products\/improved-racing-ls-billet-rear-passage-plug-gm-gen-iii-iv-barbell-cnc-6061-t6-dual-o-ring-seal","provider":"North Trail Auto","version":"1.0","type":"link"}