KPY M11 x 2.00 Thread Chaser for LS Engines – Replacement for 9120011, Hardened Steel

KPY's M11 x 2.00 thread cleaning chaser is a hardened-steel replacement for OEM 9120011 / 912-0011 designed to clean and restore LS engine head-bolt threads for smooth, secure installation.

When you’re rebuilding or maintaining an LS-series engine, bolt threads in aluminum heads and blocks can collect corrosion, debris, or suffer minor damage that leads to cross-threading or stripped bolts. This thread chaser matches the M11 x 2.00 specification used on many GM LS engines (4.8L, 5.3L, 6.0L, 6.2L and other LS-based applications) and is made from hardened steel to withstand repeated use in professional and home garages alike. It’s intended for cleaning and restoring existing threads rather than cutting new ones, helping you get fasteners to seat properly without replacing expensive components.

How does this chaser help during an LS cylinder head install?

Using the correct-size chaser ensures head bolts run true into their holes, reducing the chance of cross-threading and uneven torque. It cleans away corrosion and trapped debris so bolts can engage the original thread profile.

• Prepares bolt holes for accurate torque readings
• Removes rust and aluminum filings that block thread engagement
• Helps avoid stripping expensive head or block threads

Is this a direct replacement for OEM part 9120011 / 912-0011?

Yes — the KPY tool is manufactured to the M11 x 2.00 profile and engineered to perform the same cleaning and restoration tasks as the listed OEM part numbers. It’s a like-for-like sizing match suitable for GM LS head bolt applications.

• Matches OEM thread pitch and diameter: M11 x 2.00
• Intended as a drop-in replacement for 9120011 / 912-0011
• Works with common LS head and block materials, including aluminum

What materials and durability can I expect from this thread chaser?

The chaser is made from hardened steel to resist wear and maintain its cutting profile through multiple uses. Because it’s a chaser (thread cleaner) rather than a full-form tap, it removes contamination and restores damaged thread surfaces without aggressive re-cutting.

• Hardened steel construction for extended life
• Designed for repeated use in shop environments
• Appropriate for cleaning soft aluminum block threads without excessive material removal

How should I use this thread chaser safely and effectively?

Use light pressure, turn the chaser in and out to clear chips, and back off frequently to remove debris. Lubricate with appropriate cutting or light oil and avoid forcing the tool if resistance indicates a more serious thread issue.

• Apply light oil or thread lubricant before use
• Turn in slowly and reverse to evacuate shavings
• Replace with a full tap only if threads are severely damaged

Who is this for? Professional mechanics, engine builders, and experienced DIYers working on GM LS engines who need a reliable M11 x 2.00 thread-cleaning tool will benefit from KPY’s hardened-steel chaser. It’s ideal for engine rebuilds, head swaps, and routine maintenance where preserving original threads is critical. If you service aluminum blocks or want to prevent time-consuming thread problems during reassembly, this chaser is a practical, cost-effective addition to your toolbox.