ARP Perma-Loc Rocker Arm Adjuster Set Thread

ARP Perma-Loc rocker arm adjusters (also called poly locks or rocker arm adjusting nuts) are made for engine builders who want rocker arm lash to stay where it was set. ARP developed the patented design to fix a common problem in high-performance engines: adjusters that work loose and need repeated re-tightening.

Key Features:

• Patented Perma-Loc design that holds adjustment without constant re-tightening
• Heat-treated all the way through, not just case hardened, which reduces thread movement
• Premium chrome moly steel construction rated at 190,000 psi tensile strength
• Precision-machined threads, square to the bottom of the adjuster so it seats evenly and loads the rocker stud around a full 360 degrees
• Flush-ground locking set screw with a flat tip, not a pointed one, for full contact on the rocker arm stud
• Exclusive 12-point head with a shouldered stop that holds the wrench in place while you lock the set screw with an Allen wrench
• No special adjusting tools required

Perma-Loc adjusters are available in several thread sizes and body diameters to suit different stud-mounted rocker arm applications. Choose the variant that matches your rocker arm stud thread and rocker design.