Looks the same order to me with reverse rotation or like some manufacturers they called the back cylinder number one.
I think I found it.
A "reverse rotation REO engine" refers to the specific counter-clockwise rotation of the original 1949 REO slant-head engine, which was designed this way because the power was taken from the camshaft, not the crankshaft. While other four-stroke engines cannot run backward without significant modification, the REO engine was designed for this unusual rotation from the factory. The intake and exhaust valves were operated by a single camshaft, allowing the engine to run backward while the output pulley still rotated in the standard direction.
REO engine reverse rotation explained
Engine design: The unique design of the early REO engines, introduced in 1949, was intentional. It was a cast-iron engine with a slanted head.
Power take-off: Power was not taken directly from the crankshaft. Instead, it was taken from the camshaft, which rotated at half the speed of the crankshaft.
Valves: Both the intake and exhaust valves were operated by a single cam lobe on the camshaft.
Resulting rotation: The crankshaft rotated counter-clockwise (backward), but the drive pulley, driven by the camshaft, rotated in the same direction as most other engines (clockwise).
Purpose: This design was a key feature of the early REO lawn mowers and snow blowers, allowing them to be used with standard-rotation drive components.
Later models: Later versions, such as the 1955 vertical shaft models, were changed to a clockwise rotation to match other engines by moving the flywheel and coil to the opposite end of the crankshaft.
