IAG Performance ARP 14mm Head Stud Set for Subaru WRX/STI/Legacy GT/Forester XT

Subaru WRX/STI/Legacy GT/Forester XT

The IAG Performance ARP 14mm Head Stud Set is the essential upgrade for any high-performance Subaru build, providing superior clamping force and reliability compared to factory head bolts. Engineered specifically for use with IAG closed deck blocks and Fire-Lock head gaskets, these ARP studs are mandatory for builds targeting serious power levels.

Key Features

• 14mm Diameter: Larger than OEM 12mm for increased clamping force and reliability
• ARP2000 Material: Premium aerospace-grade alloy steel construction
• Superior Clamping Force: Maintains head gasket seal under extreme cylinder pressures
• Precision Threads: Rolled threads for superior strength and fatigue resistance
• Complete Kit: Includes studs, washers, and premium ARP assembly lubricant
• Reusable: Can be removed and reinstalled multiple times without degradation
• Required for IAG Builds: Mandatory for IAG closed deck blocks with Fire-Lock technology

Technical Specifications

• Stud Diameter: 14mm (vs. OEM 12mm)
• Material: ARP2000 alloy steel
• Thread Type: Rolled threads for maximum strength
• Finish: Black oxide coating for corrosion resistance
• Torque Specification: Follow ARP installation instructions (included)
• Kit Contents: Complete set of studs, washers, and ARP Ultra-Torque assembly lubricant

Fitment

• Subaru WRX (2002-2014) - EJ25 engines
• Subaru STI (2004-2021) - EJ257 engines
• Subaru Legacy GT (2005-2012) - EJ255 engines
• Subaru Forester XT (2004-2013) - EJ255 engines
• Note: Block must be machined for 14mm head studs (standard on IAG closed deck blocks)

What's Included

• Complete set of ARP 14mm head studs
• Hardened washers
• Premium ARP Ultra-Torque assembly lubricant
• Detailed installation instructions with torque specifications

Why Upgrade to 14mm Head Studs?

Factory 12mm head bolts are adequate for stock power levels, but they become a critical weakness in high-boost applications. The larger 14mm diameter provides significantly more clamping force, preventing head gasket failure and head lift under extreme cylinder pressures. ARP studs also offer superior material properties and can be torqued to higher specifications than OEM bolts, ensuring your head gasket stays sealed even at 950+ BHP.

Installation Requirements

• Block Preparation: Engine block MUST be machined for 14mm head studs (standard on IAG closed deck blocks)
• Torque Wrench: Precision torque wrench required
• Assembly Lube: Use only ARP Ultra-Torque lubricant (included)
• Torque Sequence: Follow ARP's specified torque sequence and values precisely
• Professional Installation: Strongly recommended for proper installation
• Thread Preparation: Block threads must be clean and chased before installation

Compatible Products

• IAG 950 EJ25 Closed Deck Short Block (IAG-ENG-S950) - Required
• IAG Fire-Lock .051" Head Gaskets (IAG-ENG-1741) - Required
• IAG Performance closed deck blocks with 14mm head stud machining

Why ARP?

ARP (Automotive Racing Products) is the world leader in fastener technology, trusted by professional race teams and engine builders worldwide. Their proprietary ARP2000 material and precision manufacturing processes ensure consistent quality and performance. Unlike factory head bolts which are designed for single use, ARP studs can be removed and reinstalled multiple times, making them ideal for race engines that require frequent maintenance.

IMPORTANT: These 14mm head studs require the engine block to be specifically machined for 14mm studs. They will NOT fit standard Subaru blocks without proper machining. All IAG closed deck blocks come pre-machined for 14mm head studs. Professional installation and precise torque procedures are essential for proper head gasket sealing.