Choosing the right head gasket for your LS engine is critical for sealing compression and preventing coolant leaks. We researched manufacturer specifications, industry standards, and aggregated owner feedback across multiple forums to compare the top options. This guide covers seven real products, from budget-friendly replacements to high-performance multi-layer steel gaskets for boosted applications. Each pick is evaluated for performance, durability, value, ease of installation, and safety. Whether you are building a mild street engine or a turbocharged race motor, our comparison will help you decide.
| Photo | Product | Score | Buy |
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GM Genuine Parts 12589227 Head Gasket Best for Stock Rebuilds Multi-layer steel, 0.051 in. compressed thickness, OEM for LS1/LS6 |
8.7 | 🛒 Check Price |
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Cometic C4532-051 Head Gasket Best for High Boost Multi-layer steel, 0.051 in. compressed thickness, 4.060 in. bore |
9.0 | 🛒 Check Price |
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Fel-Pro LS Head Gasket Set 26363PT Best Value for Street Builds PermaDryPlus MLS, 0.051 in. thickness, includes gaskets and seals |
8.4 | 🛒 Check Price |
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Mahle Original 5742 Head Gasket OEM Quality Alternative Multi-layer steel, 0.051 in. compressed thickness, 4.065 in. bore |
8.1 | 🛒 Check Price |
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Victor Reinz 58940 Head Gasket Budget Pick Multi-layer steel, 0.051 in. compressed thickness, 4.060 in. bore |
7.8 | 🛒 Check Price |
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ARP 235-1001 Head Stud Kit Best for Stud Conversion Head stud kit for LS engines, 12-point nuts, 8740 chromoly steel |
8.2 | 🛒 Check Price |
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Hastings 1305 Head Gasket Graphite Alternative Graphite composite, 0.040 in. compressed thickness, 4.100 in. bore |
7.3 | 🛒 Check Price |
1. GM Genuine Parts 12589227 Head Gasket: Best for Stock Rebuilds
The GM Genuine Parts 12589227 is the factory gasket used on LS1 and LS6 engines. We compared its specifications to aftermarket options and found it offers reliable sealing for stock or mildly modified engines. Owner feedback consistently praises its leak-free performance and easy installation, thanks to the integrated dowels.
However, in our evaluation, this gasket is not designed for forced induction or nitrous builds. The 0.051-inch compressed thickness limits its ability to withstand high cylinder pressures. If you are building a naturally aspirated engine with moderate power goals, this is an excellent choice. But for boosted applications, skip this and consider a thicker MLS gasket.
- OEM fitment for LS1, LS6, and early LS2 engines
- Multi-layer steel design for reliable sealing
- Includes positioning dowels for easy alignment
Pros: Perfect fit for stock rebuilds; Proven durability in millions of engines
Cons: Not suitable for high boost or extreme cylinder pressure
2. Cometic C4532-051 Head Gasket: Best for High Boost
Cometic C4532-051 is a popular choice among LS engine builders pushing high boost or nitrous. We researched its construction and found it uses multiple layers of high-tensile steel with a Viton elastomer coating. Owner feedback from turbo LS builds indicates it handles over 20 psi without failure when installed correctly.
In our evaluation, the main weakness is the need for a clean, flat deck surface. Any imperfection can lead to leaks. This gasket is not forgiving of poor machining. If you are building a high-power engine with proper prep, it is a top performer. But for a budget stock rebuild, it is overkill and more expensive than necessary.
- Designed for high-horsepower LS engines up to 1000+ hp
- High-tensile steel layers with Viton coating for improved sealing
- Available in multiple thicknesses for custom compression ratios
Pros: Excellent sealing under high boost; Customizable thickness options
Cons: Requires careful surface preparation
3. Fel-Pro LS Head Gasket Set 26363PT: Best Value for Street Builds
Fel-Pro’s 26363PT set is a comprehensive solution for LS engine rebuilds. We compared its materials to OEM and found the PermaDryPlus MLS design offers improved sealing over standard graphite gaskets. Owner feedback on street-driven LS swaps highlights the convenience of having all necessary gaskets in one box.
However, in our evaluation, this set is not recommended for high-boost or racing applications. The head gaskets are 0.051-inch thick and may not withstand sustained high cylinder pressure. If you are building a daily driver or mild performance engine, this is an excellent value. But for track-only cars, look elsewhere.
- Complete set includes head gaskets, intake, and exhaust gaskets
- PermaDryPlus technology for superior fluid sealing
- Pre-applied silicone beads for easy installation
Pros: Great value for a full gasket set; Trusted brand with consistent quality
Cons: Not intended for extreme power levels
4. Mahle Original 5742 Head Gasket: OEM Quality Alternative
Mahle Original 5742 is manufactured by a company that supplies OEM gaskets to General Motors. We researched its construction and found it uses three layers of steel with an elastomer coating similar to the GM gasket. Owner feedback indicates it performs well in naturally aspirated engines up to 500 hp.
In our evaluation, the main limitation is the lack of thicker options for lowering compression. If you need to reduce compression for boost, you will need a different gasket. Also, some users reported that the bore size is slightly larger than stock, which may cause issues with some cylinder heads. It is a solid choice for stock rebuilds, but not the best for custom builds.
- OEM supplier quality for LS1, LS2, LS3 engines
- Tri-layer steel construction with elastomer coating
- Pre-coated sealing beads for reliable seal
Pros: High manufacturing precision; Good for moderate performance builds
Cons: Limited thickness options
5. Victor Reinz 58940 Head Gasket: Budget Pick
Victor Reinz 58940 is a budget-friendly MLS gasket that we evaluated for cost-conscious builders. It offers multi-layer steel construction at a price point lower than most competitors. Owner feedback on budget LS swaps shows it seals well initially, but some have reported leaks after repeated heat cycling.
In our evaluation, this gasket is suitable for low-power, low-stress applications where saving money is a priority. However, we do not recommend it for forced induction or engines that see regular track use. If you are on a tight budget and building a stock replacement engine, it may work, but be aware of potential longevity issues.
- Affordable MLS gasket for LS engines
- Includes sealing beads for improved clamping
- Compatible with LS1, LS2, LS3, LS6
Pros: Lowest price among MLS gaskets; Adequate for stock to mild builds
Cons: Less durable under high heat cycles; Some reports of leaking after multiple heat cycles
6. ARP 235-1001 Head Stud Kit: Best for Stud Conversion
While not a gasket, the ARP 235-1001 head stud kit is essential for proper head gasket sealing in high-performance LS builds. We researched its specifications and found it provides a more consistent and higher clamp load than factory bolts. Owner feedback on boosted LS engines shows that using these studs with a quality MLS gasket prevents gasket failure.
In our evaluation, the main drawback is the need for careful installation and retorquing after the first heat cycle. This adds time to the build. Also, the cost is significantly higher than bolts. If you are building a high-horsepower engine, the investment is worthwhile. But for a stock rebuild, factory bolts are sufficient.
- Includes 10 head studs, washers, and nuts
- Rated to 220,000 psi tensile strength
- Precision rolled threads for consistent torque
Pros: Superior clamping force over bolts; Reusable and adjustable
Cons: Requires retorquing after initial heat cycle; More expensive than factory bolts
7. Hastings 1305 Head Gasket: Graphite Alternative
Hastings 1305 is a graphite composite head gasket that we included for builders seeking a thin gasket to increase compression ratio. It is one of the thinnest options available at 0.040 inches. Owner feedback on high-compression NA LS engines indicates it seals well when surfaces are perfectly flat.
However, in our evaluation, graphite gaskets have inherent limitations. They are prone to failure under boost or detonation due to lower tensile strength. We do not recommend this gasket for any forced induction application. Also, graphite can degrade over time with coolant exposure. If you are building a naturally aspirated engine with precise machining and want maximum compression, this is a budget option. But for most builds, an MLS gasket is safer.
- Graphite composite material for good initial sealing
- Thinner than MLS gaskets for higher compression
- Low cost
Pros: Very affordable; Good for high compression naturally aspirated builds
Cons: Not suitable for forced induction; Can blow out under high cylinder pressure
Frequently Asked Questions
What is the best LS head gasket for boosted applications?
For boosted LS engines, we recommend the Cometic C4532-051 or similar MLS gaskets with a thickness of 0.051 inches or more. These multi-layer steel gaskets can withstand high cylinder pressures and provide excellent sealing. Always use head studs for consistent clamping force.
Can I reuse LS head gaskets?
No, head gaskets should never be reused. Once compressed, they lose their ability to seal properly. Always install new gaskets during an engine rebuild or head removal.
What thickness LS head gasket should I use?
The thickness depends on your piston deck height and desired compression ratio. Stock LS engines typically use 0.051-inch gaskets. Thicker gaskets (0.060-0.080 inch) lower compression for boost, while thinner gaskets (0.040 inch) increase compression for naturally aspirated builds. Measure your piston-to-deck clearance and consult a compression calculator.
Are MLS head gaskets better than graphite?
MLS (multi-layer steel) gaskets are generally superior for high-performance and forced induction applications due to their higher strength and resistance to blowout. Graphite gaskets are cheaper and work for low-power engines but are more prone to failure under extreme conditions.
Do I need head studs or bolts for LS head gaskets?
For stock to mild builds, factory head bolts are adequate. For high-horsepower or boosted engines, head studs provide more consistent clamping force and reduce the risk of gasket failure. ARP studs are a popular upgrade.
Our Verdict
After researching and comparing the top LS head gaskets, our top pick for most builders is the Cometic C4532-051 for its proven performance under high boost and customizable thickness options. For stock rebuilds, the GM Genuine Parts 12589227 is the best OEM choice. If you are on a budget, the Fel-Pro 26363PT set offers excellent value for street-driven LS engines.
