ARP Perma-Loc Rocker Arm Adjusters 300-8242

Until ARP introduced the patented Perma-Loc Adjuster, there wasn't a 'poly lock' on the market that you didn't have to continually tighten. The adjuster body is heat-treated all the way through (not just case hardened). This eliminates the thread 'movement' common to others. The threads are also machined exactly perpendicular to the bottom of the adjuster, so it seats evenly and applies pressure on a full 360 circle. Lastly, the set screw is machined flush on the bottom (not Pointed) so it will have optimum contact on the rocker arm stud.