Product Description
Michigan Motorsports LS1 MLS Head Gasket and 2004+ Head Bolt Kit – Pair – 3.920" Bore .051" Thickness
Fits 4.8L 5.3L 5.7L LS-Based Engines – Replaces GM 12589226 / 12498544
The Michigan Motorsports LS1 Head Gasket and Bolt Kit is the go-to solution for properly sealing your cylinder heads during a rebuild or camshaft upgrade. This kit includes two high-quality MLS (Multi-Layer Steel) LS1 head gaskets along with a full set of 2004+ style head bolts, giving you everything needed to get your LS engine back together with confidence.
These MLS gaskets are widely regarded as one of the best all-around choices for most LS builds. They are a direct replacement for LS1/LS6 GM head gaskets and are produced to OEM-level standards, ensuring proper fitment, sealing integrity, and long-term durability for both stock and performance applications.
Kit Includes
- (2) Michigan Motorsports LS1 MLS Head Gaskets – Replaces GM 12589226 / 12498544
- 2004+ Style Head Bolts (Shorter Uniform Length Design)
Head Gasket Specifications
- Bore Size: 3.920"
- Compressed Thickness: .051"
- Construction: MLS (Multi-Layer Steel)
Key Features & Benefits
- Proven LS1/LS6 Replacement Design: Direct replacement for factory GM LS1 and LS6 head gaskets, making it an ideal choice for stock rebuilds and performance upgrades.
- High-Quality MLS Construction: Multi-layer steel design provides excellent sealing under high cylinder pressure and increased heat common in modified LS engines.
- Optimized for 4.8L, 5.3L & 5.7L Builds: Ideal bore size and thickness for common LS combinations, including naturally aspirated and mild power-adder setups.
- Updated 2004+ Bolt Design: Includes the later short-length head bolt configuration introduced by GM in 2005 for consistent clamping force and simplified installation.
- Complete Reseal Solution: Everything required to properly secure both cylinder heads during a cam swap, refresh, or full engine rebuild.
Important Note on Head Bolt Style
Prior to 2004, Gen 3 and Gen 4 GM small block engines used head bolts of varying lengths. Beginning in 2005, GM transitioned to a shorter, uniform-length bolt design. Please verify which head bolt style your engine requires before ordering to ensure proper fitment.
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Great product
Parts came in time. Great Quality.
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Parts packages are amazing
Package deals and great guidance by reps.
