GM generally numbers V8 cylinders in two banks: 1–4 on the driver’s side and 5–8 on the passenger side, counting from front to rear. So the front-left cylinder is number 1, and the rear-right is number 8.
This convention is used across most GM V8 families, from traditional small-blocks to the modern LS-series, helping technicians reference ignition, fuel, and maintenance tasks consistently. The exact layout can vary slightly between engine families, so for a specific model year, consult the official service manual or a diagram for your engine.
Two-bank layout and front-to-back numbering
To map the numbers on a typical GM V8 when you’re looking at the front of the engine, use the following arrangement.
- Left-hand bank (driver's side): cylinders 1 through 4, counted from front to rear.
- Right-hand bank (passenger side): cylinders 5 through 8, counted from front to rear.
- In this arrangement, the very front-left cylinder is 1, and the very rear-right cylinder is 8.
Keep in mind that some very early GM engines or specialized variants may use different labeling; always verify with the specific engine's diagram or service manual.
Variations by engine family
GM's LS-series engines, along with the traditional Chevrolet small-block and big-block layouts, generally follow the 1–4 left bank and 5–8 right bank scheme when viewed from the front. However, differences can occur in how the bank numbers are described in manuals, and some documentation may refer to Bank 1 as the left bank (driver’s side) and Bank 2 as the right bank. When in doubt, rely on the cylinder diagram that accompanies your engine’s documentation and match it to your engine’s front view.
Practical implications
Knowing the cylinder numbering is essential for mapping firing order, coil packs or spark plug wires, diagnostic tools, and routine maintenance. For reference, many GM V8 firing orders are specific to the family, such as LS engines’ 1-8-7-2-6-5-4-3, which aligns with their cylinder numbering.
Summary
GM V8 cylinder numbering follows a two-bank layout: left bank (driver's side) contains cylinders 1–4 front to rear, right bank (passenger side) contains cylinders 5–8 front to rear. Cylinder 1 is the front-left, and cylinder 8 is the rear-right. Always confirm with the exact engine manual, as historical variations can exist across GM’s engine families.