ARP "Perma-Loc" rocker nuts are made not to loosen. Reason being, the adjuster body is heat-treated all the way through (not just casehardened), which eliminates "thread" movement. The threads are machined exactly perpendicular to the bottom of the adjuster, so it seats evenly and applies pressure on a full 360° circle. The screw is machined flush on the bottom (not pointed) to have optimum contact on the rocker arm stud.
|Make & Model||Year Range||Application Details|
|Chevrolet El Camino||1964-1977|
|Chevrolet El Camino||1978-1988||7/16"|
|Chevrolet Monte Carlo||1970-1977|
|Chevrolet Monte Carlo||1978-1988||7/16"|