When rebuilding or upgrading GM LS engines, selecting the right head bolt kit is critical for reliable clamping and performance. This guide highlights six popular 6-bolt LS head bolt options from trusted brands, focusing on OEM-replacement quality, torque-to-yield design, and compatibility across generations. The featured kits cover 4.8L to 7.0L variants, including LS1, LS2, LS3, LS6, and LS7 platforms, ensuring a proper fit for stock and moderate performance builds.
| Product | Brand | Fitment / Notes |
|---|---|---|
| Michigan Motorsports LS Head Bolt Kit (GM LS Engines) | Michigan Motorsports | Fits 2004–2013 LS engines; stock replacement; torque-to-yield bolts for both heads |
| ARP Head Bolt Kit – 12pt GM LS 04 & Later | ARP | 12-point design; LS 04 & later; compact packaging for quick install |
| Michigan Motorsports LS Head Bolt Kit (GM LS Engines) | Michigan Motorsports | Fits 1997–2003 LS1/LS6 and more; replaces GM 12498545 |
| AMS Racing Head Bolt Kit for 1997–2003 LS | AMS Racing | Full set for both heads; stock-to-high-performance compatibility |
| AMS Racing Head Bolt Kit for 2004–2014 Gen IV LS | AMS Racing | Gen IV LS bolts; complete set for both heads |
| Cylinder Head Stud Bolt Kit 12-Point (2004 Newer LS) | HNeekyr | 12-point studs; full kit for modern LS engines |
Michigan Motorsports 6-Bolt Head Bolt Kit — 2004-2013 LS
This complete head bolt kit is designed for LS engines ranging from 4.8L to 7.0L, including LS2, LS3, LS7, LQ4, LQ9, and more. The set provides torque-to-yield bolts required to fasten both cylinder heads, streamlining engine rebuilds and top-end upgrades. OEM-quality replacement notes indicate the fasteners meet or exceed factory tensile strength and torque specifications, delivering dependable clamping under high-load conditions. Built for stock or modest performance builds, these bolts support a wide range of applications with reliable clamping force.
ARP Head Bolt Kit — 12pt GM LS 04 & Later
ARP’s head bolt kit for the GM LS family uses a 12-point design optimized for even torque distribution and high clamping force. The kit is specified for LS 04 and later models, with a compact packaging footprint that helps organize components during teardown and reassembly. While exact torque specs are not included in the listing, ARP is known for premium fasteners designed to withstand demanding performance and duty cycles, making this option suitable for street and light track use.
Michigan Motorsports 6-Bolt Head Bolt Kit (1997–2003 LS)
This kit targets older LS platforms, including LS1 and LS6 variants from 1997 to 2003, with a direct replacement design for GM part 12498545. It includes a complete set of torque-to-yield bolts required to secure both cylinder heads, covering stock and performance-oriented builds. The kit’s OEM-replacement stance aims to deliver factory-level reliability and consistent clamping across driving conditions, from daily commuting to higher-rev applications.
AMS Racing 1997–2003 LS Head Bolt Kit (Full Set)
AMS Racing provides a full head bolt set compatible with 1997–2003 LS engines including LS1 and LS6 variants. The bolts align with the GM 12498545 specification and are designed as torque-to-yield fasteners, ensuring a reliable clamping force across both cylinder heads. These bolts suit stock rebuilds and moderate-performance applications, offering a straightforward replacement that preserves factory-type reliability during maintenance or upgrades.
AMS Racing Gen IV LS Head Bolt Kit (2004–2014)
Targeting 2004.5–2014 Gen IV LS engines, this AMS Racing kit includes bolts for both cylinder heads with a consistent length across the set. The design aligns with Gen IV configurations, supporting 4.8L, 5.3L, 6.0L, and 6.2L variants. The kit emphasizes complete coverage (both heads) and compatibility with high-load scenarios, making it suitable for stock rebuilds and mild performance builds that demand reliable head-clamping preservation.
Cylinder Head Stud Bolt Kit 12-Point (2004+ LS)
This 12-point stud kit is engineered for compatibility with 2004-newer LS1 and LS3 engines, including 5.3L, 5.7L, and 6.0L configurations. The precision 12-point head configuration ensures accurate torque application and strong clamping force for cylinder-head installation. The package includes a complete assortment of studs, washers, and nuts, providing a full solution for head installation on modern LS builds and extensive maintenance projects.
Buying Guide: Key Purchase Considerations
When choosing a 6-bolt LS head bolt kit, consider compatibility with your engine generation, intended use, and installation complexity. Torque-to-yield designs are common for LS head bolts, offering consistent clamping and a known failure mode that should be followed with proper torque sequences. For daily drivers, OEM-replacement kits from Michigan Motorsports or AMS Racing offer reliable performance with straightforward installation. For enthusiasts pursuing optimized clamp loads, ARP and high-quality stud kits provide exceptional strength, though they may require more precise torque procedures and clearances. Always verify engine model, year, and head bolt length requirements before purchasing. A complete set for both cylinder heads is generally preferable to avoid missing hardware during reassembly. Consider drift in head thickness and gasket compatibility when selecting a kit designed for stock versus performance applications.
Comparison at a glance:
- OEM-replacement vs. premium-grade hardware: OEM-style bolts from Michigan Motorsports and AMS Racing favor reliability and straightforward installs; ARP and stud kits emphasize maximum clamping and durability under high load.
- Gen I/II vs. Gen IV compatibility: Gen IV kits are designed to fit 2004–2014 LS engines with uniform bolt lengths, while older-generation kits may require specific bolt lengths for proper fitment.
- Complete head coverage: Most kits include bolts for both cylinder heads, reducing the risk of missing fasteners during assembly.
- Installation considerations: Torque-to-yield bolts require careful torque sequence and often new gaskets; studs may simplify repeated removals but require torque-to-stud sequences.
Choosing the right 6-bolt LS head bolt kit involves aligning engine family, build goals, and installation preferences. The selections above provide a spectrum from stock-replacement reliability to high-strength performance-oriented hardware, helping you maintain proper head clamping across daily driving and moderate-performance applications.