ARP High Performance series rocker arm studs are ideal for ET bracket racing, limited rule oval track competition, and street use. They are made from 8740 chromoly steel and are heat-treated to 180,000 psi tensile strength. These studs are concentric within .005 T.I.R. thread pitch to thread pitch, which will give you more consistent rocker geometry. With an extra-large radius base, these studs are more resistant to flex and will provide a more positive seating. These rocker arm studs are designed to be used with Perma-Loc adjusters (not for use with OEM-style, self-locking nuts).