{"product_id":"proform-pr66755-self-locking-wedge-header-bolts-hex-head-steel-nickel-plated-8mm-x-1-25-chev-5-7-6-0l-ls1-ls6-set-of-12","title":"Proform PR66755 Self-Locking Wedge Header Bolts Hex Head Steel Nickel Plated 8mm x 1.25 Chev 5.7 6.0L LS1 LS6 Set Of 12","description":"\u003cp\u003eEach PROFORM Grade 8 Header Bolt is permanently assembled with a pair of special washers. When the bolt is torqued to 28+ ft-lbs, the washers super-hardened external teeth bite into and grip the bottom of the bolt head and the top surface of the header. After being self-locked in this manner, any bolt-loosening rotation is blocked by a wedge-locking action created by the washers interfacing, matching cams. Its an uphill climb: vibration that might ordinarily loosen the bolt actually increases the wedge-locking tension, securing the bolt even more. Because this simple wedge-locking method uses tension instead of friction, contact with oil actually facilitates the wedge effect. When changing headers, PROFORM Header Bolts can be untightened with a normal wrench, lubricated, and reused.\u003c\/p\u003e  \u003cp\u003e\u003cstrong\u003eFeatures:\u003c\/strong\u003e\u003c\/p\u003e  \u003cul\u003e  \u003cli\u003eGrade 8 (12.9) Steel\u003c\/li\u003e  \u003cli\u003eHex Head Type\u003c\/li\u003e  \u003cli\u003e1.181-inch Length\u003c\/li\u003e  \u003cli\u003eFits GM LS Engines with 1\/4-inch Wide Flange\u003c\/li\u003e  \u003cli\u003eSold as One Set of 12 Pieces\u003c\/li\u003e \u003c\/ul\u003e \u003cbr\u003e\u003cbr\u003e","brand":"Proform Parts","offers":[{"title":"Default Title","offer_id":44879451324727,"sku":"PR66755","price":78.65,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0680\/9364\/1015\/files\/130638.jpg?v=1780480269","url":"https:\/\/enginemaster.com.au\/products\/proform-pr66755-self-locking-wedge-header-bolts-hex-head-steel-nickel-plated-8mm-x-1-25-chev-5-7-6-0l-ls1-ls6-set-of-12","provider":"Engine Master","version":"1.0","type":"link"}