Ford Main Stud Kit

The ARP Ford Main Stud Kit (Model 256-5701) is a chromoly fastener assembly engineered for Ford modular engine builds requiring maximum reliability under sustained load and thermal cycling. This complete main stud kit delivers the clamping force consistency critical to engine builders and performance enthusiasts working with 4-bolt main configurations, where consistency between cycles directly impacts long-term durability and peak power output.

The kit features premium chromoly construction with black oxide finish to resist corrosion and galling during installation. The 12-point nut design provides six load-bearing contact points per fastener, distributing clamping loads more evenly than traditional hex nuts and reducing the risk of thread stripping or fastener rotation under engine stress. Inclusion of a windage tray accommodates the specific crankshaft geometry of Ford modular engines, ensuring proper fitment and clearance during assembly. ARP's stud-and-nut system maintains bore concentricity within tighter tolerances than individual bolt solutions, a critical factor when precision-honing main bearing bores.

This main stud kit is purpose-built for Ford modular engine platforms—including 4.6L, 5.4L, and related displacements—where OEM fasteners often prove insufficient for boosted applications, high-RPM operation, or forced-induction tuning. Engine builders installing aftermarket crankshafts, upgrading compression ratios, or running sustained high-load dyno testing depend on main stud assemblies to prevent block flex and bearing distress. The ARP 256-5701 provides repeatable clamping preload across all four main bearing caps, reducing bearing spread and extending engine life in street and competition builds alike.

ARP remains the reference standard for high-performance fastening in engine assembly, with verification protocols that ensure each stud meets published tensile strength and load-retention specifications. The Ford Main Stud Kit 256-5701 is supplied complete with studs, 12-point nuts, and windage tray—no additional fasteners required. Weight is 3.05 lbs per kit.