Mopar Deluxe Air Cleaner Nut Black Crinkle

The Mopar Deluxe Air Cleaner Nut Black Crinkle (MPN 440-339) is a precision-engineered fastener designed for classic and modern Mopar engine builds, offering both functional security and authentic factory aesthetics. This component serves as the mounting nut for air cleaner assemblies on Chrysler, Dodge, and Plymouth applications, securing the air filter housing to the carburetor or intake manifold flange. For restoration enthusiasts and performance builders alike, using OEM-specification hardware ensures proper fit, eliminates vibration-induced loosening, and maintains the visual integrity of an engine bay with period-correct detailing.

Manufactured by PROFORM with precision tolerances, this deluxe air cleaner nut features dual-thread capability, accommodating both 1/4-20 inch and 5/16-18 inch studs commonly found across Mopar engine platforms. The black crinkle finish provides a factory-authentic appearance while the aluminum construction keeps weight minimal—critical in performance applications where unsprung mass impacts handling. The iconic black Mopar Omega logo embossed on the nut serves as both identification and a visual signature of Mopar heritage, making it essential for concours-correct restorations or builds where originality matters as much as functionality.

Whether you're completing a 440 Magnum rebuild, restoring a vintage B-body, or assembling a modern Mopar performance engine, the dual-thread design eliminates guesswork during reassembly. Mechanics and DIY builders benefit from PROFORM's attention to detail—proper torque on this fastener (typically 12–15 ft-lbs) ensures the air cleaner assembly remains secure under engine vibration and thermal cycles. At just 0.12 lbs and compact 4 x 1.5 x 6-inch dimensions, it ships easily and installs in seconds, making it an ideal spare or upgrade for any serious Mopar shop or home garage working on first-gen to modern Chrysler platforms.