The front-most cylinder on the passenger-side bank of the engine is cylinder number 1. In other words, when you stand in front of a GM 5.3-liter LS-based V8 and face the vehicle, cylinder 1 sits on the right-hand side at the front of the engine.
Location and numbering on the 5.3L V8
GM’s LS-based 5.3L V8 divides its cylinders into two banks: odd-numbered cylinders (1, 3, 5, 7) sit on the passenger side, and even-numbered cylinders (2, 4, 6, 8) sit on the driver side. The front-most cylinder on the passenger side is cylinder 1, while the front-most on the driver side is cylinder 2. So cylinder 1 sits at the front of the right-hand bank, near the timing cover.
Firing order context
For reference, the firing order on these engines is 1-8-7-2-6-5-4-3, which helps with ignition coil sequencing and troubleshooting. This order aligns with the cylinder numbering described above.
How to verify on your engine
When looking at the engine with the vehicle’s front facing you, locate the passenger-side bank (the right-hand side from your viewpoint). Count from the front toward the rear along that bank: the first cylinder you encounter is 1. That differentiates it from the driver-side front cylinder, which is 2.
Summary
On a 5.3-liter GM LS-based V8, cylinder 1 is the front-most cylinder on the passenger-side bank (the right side when facing the front of the engine). The odd-numbered cylinders occupy the passenger side (1, 3, 5, 7) and the even-numbered cylinders occupy the driver side (2, 4, 6, 8), with a firing order of 1-8-7-2-6-5-4-3 guiding ignition work.