The firing order for a 5.7-liter Chevrolet V8 depends on the engine family. The classic Gen I small-block (LT1-era) engines use 1-8-4-3-6-5-7-2, while the newer Gen III/LS-based 5.7 engines use 1-8-7-2-6-5-4-3.
Two main 5.7-liter families
Chevrolet’s 5.7-liter V8 has two primary generations in common use, each with its own firing order. Knowing which family you have is essential for proper spark timing and wiring.
Gen I small-block 5.7 (LT1) firing order
Used in older 5.7 V8s like LT1-equipped Chevys from the late 1980s to mid-1990s. This generation follows the traditional small-block firing sequence.
- 1
- 8
- 4
- 3
- 6
- 5
- 7
- 2
This is the standard firing order for Gen I 5.7L small-blocks and is tied to the distributor-based ignition system used on those engines.
Gen III/LS-based 5.7 firing order
Used on LS1/5700-based 5.7 engines, including many Corvettes, Camaros, and trucks from the late 1990s onward. This generation uses a different firing order due to its coil-on-plug design and cylinder head/valve train configuration.
- 1
- 8
- 7
- 2
- 6
- 5
- 4
- 3
The Gen III/LS 5.7 firing order is standard across LS-based engines, though always verify against your vehicle’s manual or engine code for any variants.
Summary
To determine the firing order on a 5.7 Chevy, identify which generation you have: Gen I small-block LT1 uses 1-8-4-3-6-5-7-2, while Gen III/LS-based 5.7 uses 1-8-7-2-6-5-4-3. Use the correct order to route spark plug wires or coil packs and align timing components accordingly.