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Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallThe LS7 is the larger, higher-output engine in the Chevrolet Performance configurations compared here: 7.0 liters and 505 hp, versus the LS3’s 6.2 liters and 430 hp. Both are aluminum-block Gen IV small-block V8s, but the LS7 has a longer stroke, slightly higher compression, and specialized valve hardware. These are manufacturer ratings for specified configurations, not guaranteed results for every vehicle or modified engine.
LS3 vs. LS7 specifications
| Specification | LS3 | LS7 |
|---|---|---|
| Displacement | 6.2L / 376 cu. in. (Chevrolet Performance LS3 product page) | 7.0L / 427 cu. in. (Chevrolet Performance LS7 crate-engine guide) |
| Bore × stroke | 4.065 × 3.622 in. (Chevrolet Performance LS3 product page) | 4.125 × 4.000 in. (Chevrolet Performance LS7 crate-engine guide) |
| Compression ratio | 10.7:1 (Chevrolet Performance LS3 product page) | 11.0:1 (Chevrolet Performance LS7 crate-engine guide) |
| Catalog horsepower | 430 hp | 505 hp |
| Catalog torque | 425 lb.-ft. | 470 lb.-ft. |
| Notable listed hardware | Aluminum L92-style cylinder heads; 2.165-in. intake and 1.590-in. exhaust valves (Chevrolet Performance LS3 product page) | Forged-steel crankshaft; 2.20-in. titanium intake valves and 1.61-in. sodium-filled exhaust valves (Chevrolet Performance LS7 crate-engine guide) |
The horsepower and torque figures are the configurations listed in Chevrolet Performance’s 2024 catalog; they are manufacturer specifications, not independent test results. That catalog lists the LS3 at 430 hp and 425 lb.-ft., and the LS7 at 505 hp and 470 lb.-ft. (Chevrolet Performance 2024 catalog.)
Why the LS7 is larger and more powerful on paper
More displacement from bore and stroke
The LS7’s 427 cubic inches are 51 more than the LS3’s 376. It gets there with both a wider bore (4.125 inches versus 4.065) and a substantially longer stroke (4.000 inches versus 3.622). Displacement alone does not determine an engine’s output, but it is a central difference between these two designs.
Higher catalog output
In the rated configurations in Chevrolet Performance’s 2024 catalog, the LS7 is rated 75 hp and 45 lb.-ft. above the LS3. Treat those as differences between the catalog configurations, not as guaranteed gaps in every vehicle installation. Vehicle setup, engine configuration, and modifications can change the result.
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- 【Widely Application】For GM LS3/LS4/LS7/LT Engines (Pre And Post HEI Vehicles). Check your vehicle with the size as the picture shows to match your needs.
- 【Why need to replace the Spark Plug Wire】Over time, spark plug wires can become worn or damaged, causing problems with engine performance.
- 【Function】Connect the coil that houses the initial spark to the spark plugs. Provide the electrical power to fire the engine spark plugs and start the engine.
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What the hardware differences tell you—and what they don’t
The LS7 specification sheet lists an 11.0:1 compression ratio, forged-steel crankshaft, titanium intake valves, and sodium-filled exhaust valves. The LS3 listing specifies a 10.7:1 compression ratio and aluminum L92-style heads. These details distinguish the engines’ listed hardware, but the parts list alone does not establish reliability, maintenance cost, or service life.
Which engine should you choose?
Choose by the build’s goals and constraints
If your priority is the higher-output manufacturer configuration, the LS7 leads on both displacement and catalog horsepower and torque. The LS3 is the smaller-displacement alternative and has a current Chevrolet Performance product page. Neither is a universal winner: the right choice depends on the exact application and build.
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- Michigan Motorsports buys Delphi LS7 Lifters in very large quantities in order to offer the best price available. See pictures for details. Lifters are packaged in sets of 16 and include new OEM Quality Guide Trays.
- OEM-Quality Delphi LS7 Lifters – Includes 16 Delphi LS7 hydraulic roller lifters and 4 lifter guide trays, offering a direct replacement for worn or damaged lifters in GM LS-based engines.
- Direct Replacement for GM Part Numbers: Replaces GM 12499225 and 25341990, ensuring precise fitment and compatibility with factory lifter guides for reliable performance.
- Compatible with Multiple LS Engines: Designed for use in LS1, LS2, LS3, LS6, LQ4, LQ9, LY5, LY6, LM7, and other LS-based 4.8L, 5.3L, 5.7L, 6.0L, and 6.2L engines, making them ideal for rebuilds, LS swaps, and valvetrain upgrades.
- Perfect for Camshaft Upgrades: Optimized for hydraulic roller camshaft applications, these lifters provide enhanced power and torque for naturally aspirated, turbocharged, or supercharged LS engines.
Check availability and fitment before planning around either engine
Chevrolet Performance’s 2024 catalog marks its listed LS7 crate-engine part discontinued. That is not a complete picture of every possible source or current inventory, so confirm the exact part number and present availability before making a purchase plan. The LS3 also has a current product listing, but a product page is not a guarantee of local stock.
For a swap or build, verify the specific engine configuration, vehicle fitment, fuel and cooling needs, drivetrain support, installation costs, and supply. The manufacturer specifications cited here do not establish universal swap compatibility, total installed cost, or comparative reliability.
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- Complete LS Valvetrain Kit – Includes 16 Delphi LS7 hydraulic roller lifters, 4 lifter guide trays, and 16 7.400” chromoly pushrods for a full top-end refresh.
- Genuine Delphi LS7 Lifters – The industry standard for LS performance builds, offering improved oiling, stability, and quiet operation even with aggressive cam profiles.
- 7.400” One-Piece Chromoly Pushrods – Precision-machined and heat-treated for exceptional rigidity and durability, ensuring accurate valve timing under high RPM.
- High-Strength Lifter Guide Trays – Keep lifters properly aligned and secure during operation, reducing the risk of rotation or valvetrain failure.
- Wide LS Engine Fitment – Fits 4.8L, 5.3L, 5.7L, 6.0L, and 6.2L engines including LS1, LS2, LS3, LS6, LQ4, LQ9, LY5, LY6, and LM7.
Why LS3 torque figures may differ by source
Chevrolet Performance’s current LS3 product page and its 2024 catalog list 425 lb.-ft. A 2011 GM Performance Parts catalog lists 424 lb.-ft. These are source- and configuration-specific catalog figures; identify the catalog when quoting them rather than treating the one-pound difference as a universal specification. (2024 catalog; 2011 catalog.)
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- 【OEM Part Number】12499225 12564012 12576400 12648846 17089852 17109057 17120090 17120735 17121905 17122490 5233745 5234660 5234670 5234890 5235498 8171224900 25341990 12699845
- 【Fitment】Compatible with Camaro and Firebird 1999-2002, For Camaro 2010-2013, For Corvette 1999-2013, For Pontiac GTO 2004-2006, For Cadillac CTS-V 2004-2007, For Pontiac G8 2008-2009, For Tahoe, For Yukon, For Escalade 2000-2013, For Hummer H2 2003-2009, For Silverado and Sierra (4.8L, 5.3L, 6.0L) 1999-2013; Fit For GM LS1, LS2, LS3, LS6, LS7, LS9 LSX engines (4.8L, 5.3L, 5.7L, 6.0L, 6.2L)
- 【Strict Quality Control】Hydraulic roller valve lifter manufactured in TS16949 certified facilities, undergone material validation and functional testing to ensure its performance.
- 【Better Performance】The Hydraulic Roller Lifters are made of high-quality metal materials, which are wear-resistant and durable, not easy to damage, and have long service life. Precise valve timing and lift control greatly Improve fuel economy and enhance engine performance.
- 【Warranty】This hydraulic roller valve lifter kit provides a 1-year replacement or 50000km promise. If you have any problems with the AULINK product, please feel free to contact us via Amazon message.
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- 【OE Number】9070C. Please note that our spark plug wire set fits GM LS3/LS4/LS7/LT engines.
- 【Features】Our spark plug wires feature ceramic sheaths that offer exceptional heat resistance. They perform reliably even in high-temperature summer conditions.
- 【Attention】Spark plug wire may wear out or become damaged after prolonged use, leading to issues such as unstable engine idling, reduced power output, and abnormal increases in fuel consumption. You may need to replace it when these occur.
- 【Compatible with Chevy】Corvette 6.0L 6.2L 7.0L 2005-2008 | Express 1500 5.3L 2008 | Express 2500 4.8L 6.0L 2008 | Express 3500 4.8L 6.0L 2008 | Impala 5.3L 2006-2008 | Monte Carlo 5.3L 2006-2007 | Avalanche 5.3L 6.0L 2007-2008 | Silverado 1500 4.8 5.3L 6.0L 2007-2008 | Silverado 2500HD 6.0L 2007-2008 | Silverado 3500HD 6.0L 2007-2008 | Suburban 1500 5.3L 6.0L 2007-2008 | Suburban 2500 6.0L 2007-2008 | Tahoe 4.8L 5.3L 6.0L 2007-2008 | SSR 6.0L 2005-2006 | Trailblazer 5.3 6.0L 2006-2008 | Trailblazer EXT 5.3L 2005-2006.
- 【Compatible with GMC】Envoy 5.3L 2005-2008 | Envoy XL 5.3L 2005 | Savana 1500 5.3L 2008 | Savana 2500 4.8L 6.0L 2008 | Savana 3500 4.8L 6.0L 2008 | Sierra 1500 4.8L 5.3L 6.0L 6.2L 2007-2008 | Sierra 2500HD 6.0L 2007-2008 | Sierra 3500HD 6.0L 2007-2008 | Yukon 4.8L 5.3L 6.0L 2007-2008 | Yukon XL 1500 6.0L 6.2L 2007-2008 | Yukon XL 2500 6.0L 2007-2008.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
