ARP Main Bolt Kit

Part #: 260-5401

Overview

The ARP EJ20/EJ25 Main Bolt Kit is a high-performance fastener set designed specifically for Subaru engines, including EJ20 and EJ25 models. Crafted for professional engine builders and serious enthusiasts, these bolts provide a reliable upgrade over OEM fasteners, ensuring optimal engine integrity during high-stress conditions. Made from premium materials and engineered for durability, this kit helps maintain proper engine alignment and secure critical components, supporting both performance and longevity. Whether you're rebuilding or upgrading your Subaru engine, these main bolts are an essential component for ensuring a secure and reliable assembly.

Key Features

This ARP main bolt kit features advanced manufacturing and design elements that enhance engine reliability and performance:

• Forged from 8740 chromoly steel for exceptional strength and durability
• Rated at 180,000 psi tensile strength for high-stress applications
• Rolled threads after heat treatment for increased fatigue resistance
• Reduced wrenching head design for easier installation in tight spaces
• Large underhead radius to distribute load evenly and prevent stress concentrations
• Precisely engineered to meet or exceed OEM standards for fitment and performance
• Designed to withstand the demanding conditions of high-performance and racing engines

Construction & Design

The ARP main bolts are meticulously forged from 8740 chromoly steel, a material renowned for its strength and resilience under extreme conditions. The rolled threads are heat-treated to enhance fatigue life and reliability, ensuring consistent performance over time. The reduced wrenching head design allows for easier installation and removal, especially in confined engine bays, while the large underhead radius helps distribute stress evenly across the bolt, reducing the risk of failure.

Installation & Fitment

Proper installation of these main bolts requires torque specifications to be followed precisely, and it is recommended to verify fitment against your specific Subaru model and engine configuration. The kit is designed as a direct replacement for OEM fasteners, simplifying the upgrade process and ensuring a secure fit.

What’s Included

The package includes a complete set of ARP main bolts tailored for EJ20 and EJ25 Subaru engines, along with any necessary hardware for installation. Please refer to your vehicle's service manual for detailed torque procedures and installation guidelines.