10/20/2026
1-8-7-2-6-5-4-3. If you’ve ever read that off a valve cover and wondered who decided it, here’s the short version.
Chevy numbers its cylinders the same way on every V8: number one is the first cylinder on the driver side, odds run down that bank, evens run down the passenger side. The firing order is just the sequence the plugs fire in, one every 90 degrees of crank rotation. Two full turns and all eight have fired.
The old small block ran 1-8-4-3-6-5-7-2 for decades. Look closely and you’ll see cylinders 5 and 7 fire back to back, right next to each other, in the back corner of the engine farthest from the water pump. That corner runs hot and it loads the crank unevenly.
When GM built the LS in the late 90s they swapped the 4 and 7 and the 2 and 3 in the sequence. Same engine numbering, different order. The back-to-back pair moved up front where the coolant is freshest, the crank sees a more even load, and the engine runs smoother. Racers had already figured this out with custom cams, the 4/7 swap, long before it was stock. And if that order looks familiar to a Ford guy, it should. It’s the same physical pattern Ford had been running on the 5.0 and 351W for years, just with different numbers painted on the cylinders.
One thing to notice in the slow motion: every piston comes to the top twice per cycle. It only fires on one of them. The other time it’s pushing exhaust out. So if you see two pistons up at once, that’s not a mistake, that’s a four stroke doing its job.
Shaka if you learned something. Firing orders for the LT, the big block, and the one you can’t find are next.