The Gen IV LS: A Legend of Modular Power
The Generation IV Small-Block V8 represents the pinnacle of GM's pushrod engineering. Renowned for its exceptional power-to-weight ratio and robust modular architecture, the LS family spans displacements from 4.8L to 7.0L. With high-flow cylinder heads and strengthened blocks, these engines deliver unmatched reliability and performance for both factory applications and high-performance swaps.
Gen IV Technical Data
Architecture
V8 Engine Configuration
90-Degree Cylinder Angle
Deep-Skirt Block Design
Dimensions
Displacement: 4.8L to 7.0L
4.4-Inch Bore Centers
Block: Cast Iron or Aluminum
Valvetrain
Pushrod Overhead Valve (OHV)
Two Valves per Cylinder
Variable Valve Timing (VVT) Enabled
LS Engine Variants
LR4: Cast iron block used in GMT800 trucks.
LY2: Iron block replacement for LR4 without AFM or VVT.
L20: Features Variable Valve Timing (VVT) for improved efficiency.
LM7: Iron block workhorse of SUV and truck lines.
L33: High-output aluminum block version (HO).
LH6: First Gen IV 5.3L with Active Fuel Management (AFM).
LY5: Standard cast iron block with AFM system.
LC9: Aluminum block with AFM and Flex-Fuel capability.
LS1: The pioneer aluminum block LS engine.
LS6: Higher performance LS1 with aggressive cam and better flow.
LS2: Aluminum block found in Corvette, GTO, and Trailblazer SS.
LY6: Iron block with VVT, prominent in HD truck applications.
L76: Aluminum block featuring AFM for sedan applications.
L98: Performance 6.0L without AFM for Holden vehicles.
LS3: Naturally aspirated high performance standard.
L92: Found in Escalades; features high-flow rectangular heads and VVT.
LSA: Supercharged variant used in CTS-V and ZL1 Camaro.
LS9: High-output supercharged engine for the Corvette ZR1.
LS7: Hand-assembled 427 CI naturally aspirated powerhouse with titanium internals.
THE ULTIMATE SWAP ARCHITECTURE
The Gen IV LS platform is the gold standard for resto-mods and competition builds. With massive aftermarket support, compact physical dimensions, and a simplified wiring architecture, it provides the most efficient performance-per-dollar ratio in the automotive industry.