Distinguish the application
Engine-internal timing chains and final drive chains serve different applications. Identify the application before comparing numbers.
Identify construction and plate lacing
Separate roller/bush construction from silent inverted-tooth construction. 2×3, 3×4 and 4×5 describe plate lacing, not chain length.
Check length and critical dimensions
Supply link count, pitch, width, pin dimensions, tooth profile and guide arrangement. Dimension symbols and measurement points can differ between catalogues.
Confirm against the engine reference
Model, year, market, engine code and OE number help the review. A replacement still needs the correct chain construction and dimensions.