12557840 Harmonic Balancer Bolt 10.9 Grade Performance Upgrade for GM LS Engines (LS1/LS2/LS3/LS6/LQ4/LQ9) 4.8L 5.3L 6.0L 6.2L - Replaces 917-139, Excludes LS7/LS9

12557840 Harmonic Balancer Bolt

• High-Performance Harmonic Balancer Bolt: This 12557840 harmonic balancer bolt is a 10.9-grade performance upgrade specifically designed for GM LS engines. It provides enhanced strength and reliability compared to the standard bolt, ensuring optimal performance and durability.
• Compatible with Multiple GM LS Engine Models: This bolt is compatible with a wide range of GM LS engines, including LS1, LS2, LS3, LS6, LQ4, and LQ9, as well as 4.8L, 5.3L, 6.0L, and 6.2L engines. It replaces the original part number 917-139, making it a perfect upgrade for your engine.
• Excludes LS7 and LS9 Engines: Please note that this bolt is not compatible with LS7 or LS9 engines. It is specifically designed for the other GM LS engine variants listed above, ensuring a precise fit and optimal performance.
• Enhanced Durability and Strength: Made from high-quality materials, this 10.9-grade bolt offers superior strength and durability. It is designed to withstand the demands of high-performance engines, providing a reliable and long-lasting solution.
• Easy Installation and OEM Replacement: This harmonic balancer bolt is easy to install and serves as a direct replacement for the original part. It meets or exceeds OEM specifications, ensuring a seamless fit and reliable performance. Upgrade your engine with confidence and enhance its overall performance.