Mr Gasket Headlock Locking Header Bolts - M8-1.25 x 25mm - Set of 12 - 2235GFits GM LS or LT Series Engines Part Number: 2235G Headlock Bolts eliminate the need for lock washers, Period. That's because each Headlock Bolt features 24 equally spaced, stainless steel teeth serrations that bite into and hold onto the attaching surface eliminating the need for lock washers. Features and Benefits 12 per Package Includes Ball Head Socket Tool to Start Header Bolt Into Head 410 stainless steel Minimum 180,000 PSI tensile strength 24