{"product_id":"proform-66752-3-8-inch-x-3-4-long-wedge-rock-rock-header-bolt-16-pack","title":"PROFORM 66752 3\/8 inch x 3\/4 Long Wedge Rock Rock Header Bolt 16 Pack","description":"Big Block Chevrolet, Big Block Mopar 413, Small Block Ford 3\/8\" Diameter x 3\/4\" Length. black oxide. 16\/pkg compatible: GM BB 396-502 (348 \u0026amp; 409, Ford 5.0L, SBF 289-302-351W, excluding Mopar 413 3\/8\" bolts) Note: 3\/4\" long bolts are commonly used with cast iron heads. 1 inch long bolts are recommended for aluminum heads. \u003cbr\u003e\u003cbr\u003e \n Each PROFORM Grade 8 header bolt is permanently assembled with a special washer. When the bolt is torqued beyond 28 feet, the washer's super-hardened external teeth bite and grip the bottom of the bolt head and the top surface of the header. After self-locking in this manner, bolt loosening rotation is blocked by the wedge-locking action created by the washer interface, matching cam. Uphill Climbing: Vibrations can loosen the bolt and actually increase the tension on the wedge lock, further securing the bolt. It's a simple wedge-lock system that uses tension instead of friction, so contact with oil actually adds a wedge effect. When changing headers, PROFORM header bolts can be untightened with a regular wrench, lubricated and reused. \u003cbr\u003e\u003cbr\u003e \u003cbr\u003eManufacturer: ‎Proform\u003cbr\u003ePart number: ‎66752\u003cbr\u003eItem weight: ‎308 g\u003cbr\u003eProduct size: ‎15.24 x 5.08 x 12.7 cm; 308.44 g\u003cbr\u003e Material: ‎Alloy steel. \u003cbr\u003eHead Style: ‎Hexagonal\u003cbr\u003eBatteries included: ‎No\u003cbr\u003eBatteries used: ‎No\u003cbr\u003eProduct dimensions (Length x Width x Height): ‎15.2 x 5.1 x 12.7 cm","brand":"Auto Parts Tokyo","offers":[{"title":"Default Title","offer_id":47845986992448,"sku":"B00BF2Y0EO","price":120.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0853\/2584\/0704\/products\/61jTHt0KKxL._AC_US1000_fd4eed15-7c61-47cc-b25a-addfcff4c1df.jpg?v=1707677321","url":"https:\/\/megashopjapan.com\/products\/proform-66752-3-8-inch-x-3-4-long-wedge-rock-rock-header-bolt-16-pack","provider":"Mega Shop Japan","version":"1.0","type":"link"}