Chevrolet Performance LS376/525 Crate Engine

Engine Specifications

The Chevrolet Performance LS376/525 crate engine is a high-output Gen IV LS-series small-block V8 designed for performance street applications and classic vehicle swaps.

• Engine Family: Gen IV LS-Series Small-Block V8
• Displacement: 376 cubic inches (6.2L)
• Bore x Stroke: 4.065 in. × 3.622 in. (103.25 mm × 92 mm)
• Engine Block: Cast aluminum with six-bolt, cross-bolted main bearing caps
• Crankshaft: Nodular iron
• Connecting Rods: Powdered metal construction
• Pistons: Hypereutectic aluminum
• Camshaft: Hydraulic roller
• Valve Lift: .525 in. intake / .525 in. exhaust
• Camshaft Duration (@ .050 in.): 226° intake / 236° exhaust
• Cylinder Heads: Cast aluminum L92-style heads with 68cc combustion chambers
• Valve Sizes: 2.165 in. intake / 1.590 in. exhaust
• Compression Ratio: 10.7:1
• Rocker Arms: Investment-cast with roller trunnions
• Rocker Arm Ratio: 1.7:1
• Recommended Fuel: Premium gasoline (92–93 octane)
• Maximum Recommended RPM: 6,600
• Reluctor Wheel: 58X
• Engine Balance: Internal

Features and Installation Notes

The LS376/525 crate engine replaces several previous Chevrolet Performance part numbers, including 19434642, 19432418, 19419866, 19370413, 19369338, and 19301360.

Please note the following before installation:

• The engine does not include an ECM/controller kit.
• A Chevrolet Performance 19354332 Engine Controller Kit, or an equivalent aftermarket system, is required and sold separately.
• Exhaust manifolds, flexplate, and flywheel are not included.
• Premium 93-octane fuel is recommended for optimal performance.
• The engine is designed to work with the Chevrolet SS oil pan assembly.
• When installing the engine into older muscle cars or classic vehicles, a Muscle Car Oil Pan Kit (Part No. 19212593) or a comparable kit is typically required.
• This engine is intended for pre-1976 street vehicle engine swaps and is not designed for marine applications.

Recommended Engine Break-In Procedure

For proper engine longevity and performance, follow the recommended break-in process.

1. Fill the engine with oil that meets dexos1 specifications. For track use or competitive driving, use Mobil 1 15W-50 engine oil.
2. Prime the engine following the proper priming procedure, then top off all required fluids, including coolant and power steering fluid.
3. Start the engine and listen carefully for any abnormal noises. If everything sounds normal, allow the engine to run at approximately 1,000 RPM until it reaches normal operating temperature.
4. During the first 30 miles (or one hour), drive the vehicle under varying loads while avoiding full-throttle acceleration and prolonged high RPM operation.
5. Perform five to six moderate-throttle (approximately 50%) accelerations to around 4,000 RPM, allowing the engine to decelerate back to idle while remaining in gear.
6. Complete two to three full-throttle accelerations to approximately 4,000 RPM, again allowing the engine to return to idle while staying in gear.
7. After the initial break-in period, replace both the engine oil and oil filter. Inspect the used oil and filter for any signs of metal particles or other contaminants.
8. Continue driving normally for the next 500 miles (or approximately 12–15 engine hours). Avoid sustained high engine speeds or heavy engine loads during this period.
9. Perform a second oil and filter change after the 500-mile break-in and inspect both for contaminants to verify the engine is operating correctly.

Emissions Information

This engine is legal for sale and installation only on non-emissions-controlled vehicles or vehicles used exclusively for closed-course competition racing. It is not intended for use in emissions-controlled street vehicles where applicable regulations prohibit its installation.

General Information

• Product Type: High-Performance Crate Engine
• Product Series: Chevrolet Performance LS3 LS376/525
• Engine Configuration: Long Block
• Engine Family: GM Gen III/IV LS
• Displacement: 6.2L (376 cubic inches)
• Power Output: 525 horsepower
• Application: Semi-universal fit for performance builds and engine swap projects

Engine Construction

• Engine Block Material: Aluminum
• Cylinder Head Material: Aluminum
• Cylinder Heads Included: Yes
• Compression Ratio: 10.7:1
• Engine Balance: Internal
• Rear Main Seal: One-piece design
• Camshaft Type: Hydraulic roller tappet

Fuel and Induction System

• Fuel System: Electronic Fuel Injection (EFI)
• Intake Manifold: Included
• Throttle Body: Included

Included Components

The LS376/525 crate engine comes equipped with several factory-installed components, including:

• Aluminum cylinder heads
• Intake manifold
• Throttle body
• Oil pan
• Water pump
• Harmonic balancer
• Flexplate
• Valve covers
• Timing cover
• Spark plugs
• Spark plug wires

Components Not Included

The following items must be sourced separately for installation:

• Air cleaner
• Engine control computer (ECM)
• Wiring harness
• Flywheel

Packaging Information

• Package Dimensions:
  • Depth: 37.5 inches
  • Width: 26.5 inches
  • Height: 31 inches
• Shipping Weight: Approximately 625 lbs