Adjuster- 5/16 dia. Cup 7/16-20 Thread

The T AND D MACHINE Adjuster with 5/16 dia. Cup and 7/16-20 Thread (MPN 03100) is a precision rocker arm adjuster engineered for fine-tuning valve clearance in small-block engine builds. This single-piece steel adjuster features a 1.130-inch shoulder length and a 5/16-inch cup design that seats securely against the rocker arm tip, allowing precise adjustment of intake and exhaust valve lash during initial setup and ongoing maintenance.

The 7/16-20 thread specification is critical for compatibility with the valve train assembly—this standardized thread size ensures proper engagement with the adjuster screw housing without risk of cross-threading or bottoming out prematurely. The 5/16-inch cup diameter provides adequate bearing surface to distribute load evenly across the rocker arm, minimizing point-loading that can lead to wear or pitting over extended use. Steel construction delivers the hardness and dimensional stability required for repeatable adjustments under thermal cycling and engine vibration.

This adjuster is essential for engine builders and performance enthusiasts working with small-block platforms where correct valve clearance directly impacts combustion efficiency, valve seating integrity, and overall reliability. Proper valve lash adjustment prevents both over-tightening (which causes valve float and increased wear) and under-tightening (which allows excessive clearance and reduces valve control). The lightweight design—0.03 lbs—ensures it integrates seamlessly into any rocker arm assembly without adding unnecessary mass to the valve train.

Individual adjusters are sold as single units, allowing builders to replace worn or damaged units without requiring a full rocker arm assembly swap. This part is a direct mechanical component with no setup or installation variations—compatibility depends entirely on matching the 7/16-20 thread specification and the 5/16-inch cup geometry to your existing rocker arm platform.