{"product_id":"fits-gm-ls-engines-with-1-4in-wide-flange","title":"Proform 66754 Fits GM LS Engines with 1\/4in Wide Flange","description":"Each PROFORM 12.9 Steel (equiv. 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. It's 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.","brand":"Proform","offers":[{"title":"Default Title","offer_id":51087832023355,"sku":"BCHW_66754","price":51.03,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0955\/5958\/2011\/files\/acd45581ee653.jpg?v=1775076626","url":"https:\/\/performancepartscanada.ca\/products\/fits-gm-ls-engines-with-1-4in-wide-flange","provider":"Performance Parts Canada","version":"1.0","type":"link"}