Michigan Motorsports LS1/LS6 MLS Head Gasket & Head Bolt Kit | Like GM #12589226 | Fits 1997-2003 4.8L 5.3L 5.7L LS Engines | Early-Style Head Bolts | OEM Replacement for Cathedral Port Heads

The Michigan Motorsports LS1/LS6 MLS Head Gasket & Bolt Kit (1997–2003) delivers OEM-quality sealing and secure head bolt clamping for your Gen III LS engine rebuild or performance refresh. Featuring two Multi-Layer Steel (MLS) head gaskets built to GM #12589226 specs (3.920″ bore, .051″ thickness) and a full set of early-style head bolts (8 long & 2 short per side), this kit is engineered for cathedral-port LS engines found in 4.8L, 5.3L, and 5.7L applications. Whether you’re performing routine maintenance, repairing a blown gasket, or building a high-performance street or race engine, this kit provides factory fit, lasting durability, and leak-free performance you can trust.

• OEM-Matched MLS Gaskets for Precision Sealing – Multi-layer steel construction delivers superior combustion sealing and coolant/oil passage alignment, matching GM 12589226 factory specs for exact fit and lasting performance.
• Full Early-Style Head Bolt Set Included – Complete hardware for both heads (8 long, 2 short per side), ensuring correct torque and clamping force for 1997–2003 LS1/LS6 engines.
• Wide Compatibility Across LS Applications – Fits cathedral-port Gen III engines including LS1, LS6, LQ4, LM7, and others in 4.8L, 5.3L, and 5.7L displacements.
• Ideal for Stock Rebuilds or Performance Builds – Perfect for OEM-style repairs, high-performance upgrades, or preventative maintenance to avoid future head gasket failures.
• Direct Replacement, Hassle-Free Install – No modifications needed; components match OEM dimensions for easy installation and reliable, factory-quality results.