{"product_id":"proform-pr66756-wedge-locking-header-bolts-16","title":"Proform PR66756 Wedge Locking Header Bolts 16","description":"\u003cp\u003eEach 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.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003e Features:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e Grade 8 (12.9) Steel\u003c\/li\u003e\n\u003cli\u003eHex Head Type\u003c\/li\u003e\n\u003cli\u003e1-inch Length\u003c\/li\u003e\n\u003cli\u003eFits GM BB 396-502 exc 348 and 409, Ford 5.0L, SB 289-302-351W, Mopar 413\u003c\/li\u003e\n\u003cli\u003eSold as One Set of 16 Pieces\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\u003cbr\u003e","brand":"Proform Parts","offers":[{"title":"Default Title","offer_id":44879654682935,"sku":"PR66756","price":81.25,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0680\/9364\/1015\/files\/130639.jpg?v=1780919513","url":"https:\/\/enginemaster.com.au\/products\/proform-pr66756-wedge-locking-header-bolts-16","provider":"Engine Master","version":"1.0","type":"link"}