Stretched Head bolts can lead to blown head gaskets and overheated engines. Head Studs offer a alternative when its time to reseal a engine head. Bolts when torqued are affected by two difference forces. The bolt stretches and twists. A Headstud will not twist as only the nut is torqued down. This allows them to add more clamping force and helps reduce the chance of burning up a gasket. Fit 2004-Newer LS1 LS3 5.3L 5.7L 6.0L engines​ / Chevy LS1 LS6 L98 4.8L 5.3L 6.0L.