Compare LS Engines

Side-by-side specs, swap difficulty, and cost estimates for any 2–3 LS variants.

Specification
LS1
Gen III · Aluminum
POPULAR
LS3
Gen IV · Aluminum
POPULAR
Displacement
5.7L / 346 ci
6.2L / 376 ci
Bore × Stroke
3.898" × 3.622"
4.065" × 3.622"
Compression Ratio
10.25:1
10.7:1
Stock HP
345 HP
430 HP
Stock TQ
350 lb-ft
424 lb-ft
Rod Length
6.098"
6.098"
Deck Height
9.24"
9.24"
Block Material
Aluminum
Aluminum
Generation
Gen III
Gen IV
RPO Code
LS1
LS3

Swap Difficulty & Cost

LS1

Easy
Difficulty3/10
Swap Cost
$3,000–$5,000
Labor
40–60 hrs
  • Lightest aluminum LS block
  • Huge aftermarket support
  • Most common swap engine

LS3

Easy
Difficulty3/10
Swap Cost
$4,000–$6,000
Labor
40–60 hrs
  • Best factory rectangle port heads
  • Most popular swap engine
  • Excellent NA potential

Factory Applications

LS1

The original Gen III LS. Aluminum block, all-new architecture. Classic swap favorite with cathedral port heads.

1997–2004 Corvette C5
1998–2002 Camaro/Firebird
2004 GTO

LS3

Top swap choice in 2026. Big bore, rectangular port heads, 430+ HP stock, massive aftermarket support.

2008–2013 Corvette C6
2010–2015 Camaro SS
2008–2009 Pontiac G8