How are cylinders numbered on a 5 cylinder 06 Chevy Colorado?

A 5-cylinder engine in a 2006 Chevy Colorado (the inline-5 2.8L LZ engine) is numbered from the timing chain end to the flywheel end. Therefore, cylinder 1 is at the front of the engine (closest to the radiator), and cylinder 5 is at the rear (closest to the transmission). They are numbered sequentially from front to rear.