IAG / JE Pro Seal Subaru EJ25 / EJ257 100mm Head Gasket 0.039in For 14mm Head Studs (1 pair)

Part Details:

The IAG Performance / JE Pro Seal Subaru MLS Head Gaskets are designed specifically for use with IAG 14mm Head Stud Sets on Subaru EJ25 and EJ257 engines. Manufactured from high-quality multilayer stainless steel, these gaskets provide the sealing strength and durability required for high-performance and high-boost engine builds.

Unlike standard head gaskets, these MLS gaskets feature enlarged head stud holes to accommodate 14mm head studs without drilling or modifying the gasket. This ensures proper fitment and consistent clamping force, making them an ideal solution for built engines and applications where increased cylinder pressure is expected.

Built for High-Boost EJ Applications

The multilayer stainless steel construction is embossed and tempered to maintain long-term sealing integrity under extreme conditions. A proprietary four-step coating process is applied after embossing, including a silicone sealing layer that enhances surface conformity and improves overall sealing performance.

With a 100mm bore size and 0.039-inch compressed thickness, these head gaskets are well suited for EJ25 and EJ257 engines using aftermarket pistons and strengthened bottom-end components.

Compatibility & Fitment

These head gaskets are designed exclusively for Subaru EJ25 and EJ257 engines equipped with IAG 14mm head stud sets. They are sold as a matched pair to support a complete engine assembly.

Key Features

• Multilayer stainless steel (MLS) head gasket construction
• Designed specifically for use with IAG 14mm head stud sets
• Enlarged stud holes for proper clearance without modification
• Embossed and tempered layers for long service life
• Proprietary four-step coating process with silicone sealing layer
• 100mm bore size with 0.039-inch compressed thickness
• Compatible with Subaru EJ25 and EJ257 engines

What’s Included

• Pair of IAG Performance / JE Pro Seal MLS head gaskets

Frequently Asked Questions

Are these head gaskets required when using 14mm head studs?
Yes. These gaskets are specifically designed to clear 14mm head studs without modification and are strongly recommended when using IAG 14mm head stud sets.

Can these be used on stock engines?
While primarily intended for built or high-performance engines, they may be used on stock EJ25 or EJ257 engines when paired with compatible components and proper machine work.

Is professional installation recommended?
Yes. Proper surface preparation, torque procedures, and installation practices are critical for MLS head gasket performance.

Learn more about IAG Performance engine and reliability solutions