Where are slant six engine numbers?

The location of the engine number on a slant six varies slightly depending on the year and model of the vehicle. However, it's generally found on the engine block itself, near the front, often on the passenger side (right side in a right-hand drive vehicle).

To be more precise, you'll need to specify the make, model, and year of the vehicle. A quick online search for "[Year] [Make] [Model] slant six engine number location" will usually yield the most accurate results. Owner's manuals or online forums dedicated to that specific vehicle are also excellent resources.