Chevy Firing Order: SBC 350, Big Block 454 and LS Engines
The small block Chevy (SBC) firing order, including the Chevy 350, is 1-8-4-3-6-5-7-2. The big block Chevy (BBC) 396, 427, 454 and 502 use the same order, 1-8-4-3-6-5-7-2. GM LS engines (Gen III and Gen IV) use 1-8-7-2-6-5-4-3. On distributor engines the rotor turns clockwise, viewed from above.
Chevy firing orders at a glance
| Engine | Firing order | Distributor rotation |
|---|---|---|
| Small block Chevy (SBC 283, 305, 327, 350, 383, 400) | 1-8-4-3-6-5-7-2 | Clockwise |
| Big block Chevy (BBC 396, 427, 454, 502, 572) | 1-8-4-3-6-5-7-2 | Clockwise |
| GM LS (LS1, LS2, LS3, LS6, LS7, LSA, truck LS) | 1-8-7-2-6-5-4-3 | No distributor (coil-near-plug) |
| GM Gen V LT (LT1, LT4, 2014-on truck 5.3L and 6.2L) | 1-7-2-6-5-4-8-3 | No distributor (coil-near-plug) |
How Chevy V8 cylinders are numbered
On small block, big block and LS Chevy V8s, the odd-numbered cylinders (1, 3, 5, 7) are on the driver’s side and the even-numbered cylinders (2, 4, 6, 8) are on the passenger’s side (in a left-hand-drive vehicle), counted from the front of the engine to the back. Cylinder 1 is the front cylinder on the driver’s side.
SBC 350 firing order and distributor wiring
- Bring cylinder 1 to top dead center on its compression stroke (both valves closed, timing mark at zero).
- Note where the distributor rotor points. That cap terminal is cylinder 1.
- Working clockwise around the cap, connect the wires in the order 1-8-4-3-6-5-7-2.
The same steps apply to big block Chevys such as the 454, since they share the firing order and rotation. See our Chevy 454 big block guide for its specs. For 350 specs and horsepower, see our Chevy 350 engine guide.
LS firing order
LS engines fire 1-8-7-2-6-5-4-3. Compared with the older small block, cylinders 4 and 7 swap places, and so do 2 and 3, which reduces crankshaft vibration. LS engines use individual coils near each plug, so there is no distributor to wire. Each coil is plugged into its own cylinder, and the ECU controls the order. GM’s Gen V LT engines, including the LT4 and the 2014-on truck 5.3L and 6.2L, use a different order: 1-7-2-6-5-4-8-3.
When the firing order can change
The firing order is set by the camshaft. Some performance camshafts for small block Chevys use a “swapped” order (often called a 4-7 swap) to smooth the engine. If your engine has one, wire it to the order the cam maker specifies, not the standard order.
Crate engines with these firing orders
Every small block Chevy crate engine and big block Chevy crate engine we sell uses a standard Chevy layout, and the LS and LT crate engines use the LS-style coil-near-plug ignition. Check each product’s description for camshaft and ignition details.
Frequently asked questions
What is the firing order for a Chevy 350?
1-8-4-3-6-5-7-2, with the distributor rotating clockwise.
Is the 454 firing order the same as the 350?
Yes. Big block Chevys such as the 454 use the same 1-8-4-3-6-5-7-2 firing order and clockwise distributor rotation as the small block.
What is the LS3 firing order?
The LS3, like other LS engines, fires 1-8-7-2-6-5-4-3.
What is the 5.3 firing order?
The Gen III and Gen IV 5.3L Vortec engines, which are LS engines, fire 1-8-7-2-6-5-4-3. The 2014-on Gen V 5.3L uses the LT order, 1-7-2-6-5-4-8-3.
What is the LT4 firing order?
The LT4 and other Gen V LT engines fire 1-7-2-6-5-4-8-3. See the LT4 engine guide for its specs.
What is the firing order of a V8 engine?
There is no single V8 firing order; it depends on the engine family. Small block and big block Chevy V8s fire 1-8-4-3-6-5-7-2 and GM LS engines fire 1-8-7-2-6-5-4-3. Ford V8s use different orders and number their cylinders differently; see the Ford firing order guide.
How are the cylinders numbered on an LS engine?
The same way as other Chevy V8s: cylinders 1, 3, 5 and 7 are on the driver’s side and 2, 4, 6 and 8 are on the passenger’s side, counted from the front of the engine.
What is the firing order for a 383 stroker?
A 383 stroker built on a small block Chevy 350 block uses the small block order, 1-8-4-3-6-5-7-2, unless it has a firing-order-swap camshaft. A 383 built on an LS block uses the LS order, 1-8-7-2-6-5-4-3. The 383 crate engines we list are all small block Chevy engines; see our 383 stroker engine guide.
Related: Ford firing orders, GM LS engines explained, what is a crate engine?, Chevy 350 engine, 6.0 LS engine, big block vs small block
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