{"product_id":"gm-3988313-genuine-gm-nos-valve-mechanism-bearing-group-0-539","title":"GM 3988313 – Genuine GM NOS Valve Mechanism Bearing (Group 0.539)","description":"\u003ch1\u003e\u003cstrong\u003eGM 3988313 — Engine Bearing (Valve Train \/ Rocker‑Related Bearing)\u003c\/strong\u003e\u003c\/h1\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eGroup 0.539 — “Valve Mechanism Bearings”\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003ch1\u003e📘 \u003cstrong\u003ePart Overview\u003c\/strong\u003e\n\u003c\/h1\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eGM Part Number:\u003c\/strong\u003e \u003cstrong\u003e3988313\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eGroup Number:\u003c\/strong\u003e \u003cstrong\u003e0.539\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eNomenclature:\u003c\/strong\u003e \u003cem\u003eBearing, Valve Mechanism\u003c\/em\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eFunction:\u003c\/strong\u003e Supports rocker arm or valve lever movement\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eEra:\u003c\/strong\u003e Late 1960s–1970s GM service part\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003ePackaging:\u003c\/strong\u003e Small GM blue‑and‑white box \u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003ch1\u003e🚗 \u003cstrong\u003eFitment (Catalog‑Based Engine Family Identification)\u003c\/strong\u003e\n\u003c\/h1\u003e\n\u003cp\u003e\u003cspan\u003eBecause GM did not publish model‑specific lists for these micro‑bearings, fitment is tied to \u003cstrong\u003eengine families\u003c\/strong\u003e, not vehicles.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eMost common engine families using 0.539 bearings:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eChevrolet Inline‑6:\u003c\/strong\u003e 194, 230, 250, 292\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eChevrolet Small‑Block V8:\u003c\/strong\u003e 283, 307, 327, 350 (select rocker support applications)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eChevrolet Big‑Block V8:\u003c\/strong\u003e 396, 402, 427, 454 (limited)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eGM Industrial \/ Marine variants\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eThese bearings typically support:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eRocker arm pivots\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eRocker shaft supports\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eValve lever pivots\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eUpper valvetrain motion points\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"CorvairFarmer","offers":[{"title":"Default Title","offer_id":48460151750907,"sku":null,"price":19.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0659\/3740\/8251\/files\/aa_f3412727-a7ad-4003-b06e-588ea53170c7.jpg?v=1773877432","url":"https:\/\/corvairfarmer.com\/products\/gm-3988313-genuine-gm-nos-valve-mechanism-bearing-group-0-539","provider":"CorvairFarmer","version":"1.0","type":"link"}