Melling MRM-1791

Melling MRM-1791 is a 5/16-24 self-locking rocker arm nut. It retains a rocker arm on its stud and maintains valvetrain adjustment in engines using adjustable stud-mounted rocker arms.

Application / fitment

The nut appears as a component in selected Melling MRK-600 and MRK-610 rocker-arm kits. Confirm rocker-stud diameter and thread pitch, rocker design and valve-adjustment method.

• part type: rocker arm nut
• selected Ford 240 / 3.9 L and 300 / 4.9 L inline-six engines with adjustable stud-mounted rockers
• selected Ford Windsor 289 / 4.7 L, 302 / 5.0 L and 351W / 5.8 L V8 engines
• component used in selected Melling MRK-600 and MRK-610 kits
• not for systems using another lock-nut type, bolt-mounted rocker or 3/8 or 7/16 in rocker studs
• internal thread: 5/16-24 UNF

Inspect the rocker-stud thread and rocker bearing surfaces before installation. Adjust the nut according to the specified valve-lash or hydraulic-lifter preload procedure. Do not reuse a worn self-locking nut if it no longer holds adjustment on the stud.

Technical information

• part type: self-locking rocker arm nut
• thread: 5/16-24 UNF
• material: steel
• finish: black oxide
• valvetrain type: adjustable stud-mounted rocker arm
• function: retains the rocker arm and maintains valvetrain adjustment
• selected kits containing this number: Melling MRK-600 and MRK-610
• OE number found in application catalogs: Ford D0AZ-6A529-A
• quantity required per engine: according to the number of adjustable rocker arms
• UPC: 729295225430
• sale unit: 1 piece