LS and LT Engine Differences: Corvette Buyer’s Parts Guide

 

By J & J Auto Wrecking, with technical insights from Car and Driver contributors

The Chevrolet Corvette has long been the flagship for GM performance, and much of that reputation comes from its legendary small-block V8 engines. For enthusiasts sourcing OEM replacement parts or complete engines, understanding the differences between the LS and LT engine families is essential.

At J & J Auto Wrecking, we specialize in tested, video-verified Corvette engines, including LS1, LS2, LS3, LT1, and LT4. Whether you're maintaining a C5, upgrading a C6, or building a performance swap project, this detailed guide explains each engine’s specifications, compatibility concerns, and what you need to know before purchasing.

The LS vs. LT Engine Evolution

Chevrolet’s modern small-block V8s fall into two primary families:

• LS-Series (Gen III & IV Small Blocks)

• Lightweight aluminum design

• Pushrod architecture

• Excellent aftermarket support

• Used in C5 and C6 Corvettes (1997–2013)

• LT-Series (Gen V Small Blocks)

• Advanced tech: direct injection, VVT, higher efficiency

• Found in the C7 Corvette (2014–2019)

• More complex electronically, less interchangeability with LS components

Both platforms deliver excellent performance, but key differences impact engine selection, part compatibility, and replacement strategy.

LS1 — The Original Modern Small Block (1997–2004 Corvette)

 

The LS1 marked the beginning of a new era when it debuted in the C5 Corvette.

• Displacement: 5.7L (346 cubic inches)

• Horsepower: ~345 hp

• Key Features:

• All-aluminum block and heads

• Cathedral port cylinder heads

• Compact design with low deck height

• Coil-on-plug ignition and returnless fuel system (later years)

Parts Sourcing Notes:

• Found in 1997–2004 Corvettes and 1998–2002 Camaros

• Early vs. late LS1 wiring and PCM differ — confirm year-specific parts

• Not all LS-series intakes and heads are compatible due to port shape

We carry tested LS1 engines and components, including complete long blocks, intake manifolds, throttle bodies, and ignition components.

LS2 — The Bridge Between LS1 and LS3 (2005–2007 Corvette)

 

The LS2 evolved the LS1 platform with more displacement and updated architecture.

• Displacement: 6.0L (364 cubic inches)

• Horsepower: ~400 hp

• Key Features:

• Retains cathedral port heads (like LS1)

• Larger 4.00-inch bore enables better cylinder head upgrades

• Higher flow intake manifold

• Improved crankshaft and block casting

Parts Sourcing Notes:

• Used in 2005–2007 C6 Corvettes and 2005–2006 GTOs

• Oil pan designs vary by chassis — important for swaps

• ECM and harness must match LS2-specific sensors and throttle body

• Compatible with many LS1 accessories but confirm fitment

At J & J Auto Wrecking, we stock tested LS2 engines, harnesses, and ECMs, including matched accessories for plug-and-play compatibility.

LS3 — The Powerhouse of the C6 Corvette (2008–2013)

The LS3 refined the Gen IV architecture with higher output and better breathing.

• Displacement: 6.2L (376 cubic inches)

• Horsepower: 430–436 hp

• Key Features:

• Rectangular port cylinder heads (unlike LS1/LS2)

• Larger valves, higher-flow intake

• Stronger block and bottom-end

• Standard in base C6 and Grand Sport Corvettes

Parts Sourcing Notes:

• ECM, harness, and sensors must be LS3-specific

• Heads, intake, and injectors are not compatible with LS1/LS2 without modification

• LS3 is a common donor engine for performance swaps due to power and availability

We offer video-tested LS3 engines and major components, including full drop-outs, heads, and matched wiring systems.

LT1 — Gen V Tech for the C7 Corvette (2014–2019)

The LT1 represented a major leap in technology for Corvette powerplants.

• Displacement: 6.2L (376 cubic inches)

• Horsepower: 455–460 hp

• Key Features:

• Direct fuel injection (first for a small-block V8)

• Variable valve timing

• Advanced combustion chamber design

• High compression ratio (11.5:1)

• Found in C7 Corvette Stingray and Grand Sport

Parts Sourcing Notes:

• Direct injection system requires matching high-pressure fuel system

• ECM, sensors, and throttle bodies are not interchangeable with LS engines

• Requires LT-specific wiring, accessories, and PCM

We supply tested LT1 engines, DI components, and matched ECMs, ensuring proper compatibility for C7 restorations or engine swaps.

LT4 — Supercharged Muscle for the C7 Z06 (2015–2019)

The LT4 took the Gen V engine architecture to the extreme.

• Displacement: 6.2L (376 cubic inches)

• Horsepower: 650 hp

• Key Features:

• Integrated Eaton TVS 1.7L supercharger

• Forged internals and upgraded cooling

• Reinforced crankshaft and pistons

• Standard in C7 Z06

Parts Sourcing Notes:

• Supercharger, heads, and fuel system are LT4-specific

• Requires compatible cooling, intercooler, and electronics

• Often used in performance swaps but demands proper support systems

We stock video-tested LT4 engines, superchargers, and full Z06 engine kits, ready for your next high-performance project.

LS and LT Compatibility Overview

Here’s a quick breakdown of key differences that affect sourcing and interchange:

What to Watch For When Buying Used Corvette Engines

• Always match RPO codes: LS1 = RPO “LS1,” LS2 = “LS2,” LS3 = “LS3,” etc.

• Check accessory compatibility: Alternators, PS pumps, oil pans can differ by year/chassis

• Verify wiring harnesses: Gen III/IV/Gen V have different plugs, sensors, and pinouts

• Ask for video testing: At J & J, all engines are test-run and verified before sale

Why Enthusiasts Trust J & J Auto Wrecking for Corvette Engines

With 65+ years of experience and a reputation for performance-focused salvage, we deliver:

• Complete LS1, LS2, LS3, LT1, and LT4 engines — tested and backed by video proof

• Drop-outs with wiring, accessories, ECMs, and sensors

• Expert guidance on compatibility and fitment

• Nationwide shipping and our exclusive Name-Your-Own-Price option

• Stock updated weekly from high-end Corvette salvage vehicles

Search Our Corvette Engine Inventory Now

Whether you need a clean LS2 for your 2006 C6, a strong LS3 dropout for a performance build, or a complete LT1 package for your C7, J & J Auto Wrecking has the parts you need, tested and ready to ship.

Browse our Corvette part listings by generation and engine code or contact our team directly for sourcing help. When it comes to OEM Corvette engines, trust the experts who’ve been serving enthusiasts since 1957.