LS vs. LT: What’s the Difference?

Your Complete Guide to GM’s Modern V8 Engines

When it comes to modern GM performance, two engine families dominate the conversation: the LS and the LT. Whether you’re building a street car, prepping for the drag strip, or planning an engine swap, understanding the difference between LS and LT engines will help you choose the right platform — and the right performance parts — for your build.

In this guide, we’ll break down LS vs. LT engines, compare performance potential, and cover what you need to know before starting your LS swap or LT swap.

The LS Engine Family – Proven Performance Since 1997

The GM LS engine made its debut in the 1997 Chevrolet Corvette C5 with the LS1. Over the years, GM produced multiple variants — LS1, LS2, LS3, LS6, LS7, LS9, and LSA — each designed to deliver more power, better efficiency, and stronger durability.

Key LS Engine Features:

• Pushrod V8 design – compact, lightweight, and simple

• Aluminum and iron block options

• Cathedral or rectangular port cylinder heads

• Massive aftermarket support for LS performance parts

• Affordable and widely available for LS swaps

Why Enthusiasts Love the LS:
The LS platform’s affordability, availability, and versatility make it the go-to choice for everything from street cars to 1,000+ horsepower drag builds. The aftermarket offers endless LS engine upgrades like intake manifolds, camshafts, cylinder heads, ignition systems, and complete LS swap kits.

The LT Engine Family – GM’s Next-Generation Power

Introduced in 2014 with the C7 Corvette Stingray, the GM LT engine builds on the LS foundation while adding cutting-edge technology for improved performance and efficiency. Variants include the LT1, LT2, LT4 (supercharged), and LT5 (supercharged).

Key LT Engine Features:

• Direct fuel injection (DI) for better fuel atomization and efficiency

• Variable valve timing (VVT) for optimized power across the RPM range

• Advanced combustion design for cleaner, more efficient power

• Higher compression ratios than most LS engines

• Stronger factory internals in performance models like the LT4 and LT5

Why Enthusiasts Love the LT:
The LT offers modern technology and massive power potential straight from the factory. With the right LT performance upgrades — such as ported heads, upgraded fuel systems, and forced induction — LT engines can deliver staggering horsepower while remaining street-friendly.

LS vs. LT – Head-to-Head Comparison

Which Engine Should You Choose?

Choose an LS Engine if:

• You want the most affordable GM V8 platform

• You’re looking for easy swaps with minimal wiring headaches

• You want massive aftermarket support for custom builds

Choose an LT Engine if:

• You want the latest GM V8 technology

• You prefer direct injection for efficiency and performance

• You’re building a newer vehicle or want the highest factory horsepower potential

Upgrading Your LS or LT Engine

No matter which platform you choose, performance upgrades can take your build to the next level:

Popular LS Engine Upgrades:

• High-flow intake manifolds

• Performance camshafts

• CNC-ported cylinder heads

• Coil packs & ignition upgrades

• Complete LS swap kits

Popular LT Engine Upgrades:

• Larger throttle bodies

• High-pressure fuel pumps

• Supercharger or turbo kits

• Ported heads & cam packages

• Direct-injection fuel system upgrades

Final Thoughts – LS vs. LT for Your Build

Both the LS and LT families deliver incredible performance potential. The LS engine is the tried-and-true choice for affordability and swap ease, while the LT engine offers cutting-edge technology and massive factory power.

At Top Street Performance, we carry a full range of LS performance parts and LT performance upgrades, including swap kits, intake manifolds, valvetrain components, and ignition systems — everything you need to unleash your GM V8’s full potential.

Shop our full selection of LS & LT engine parts today and start building the power you’ve always wanted.