* 4.3L Vortec V6: This was the base engine option.
* 5.3L Vortec V8: This was a more powerful option.
* 6.0L Vortec V8: This was the most powerful engine option and was often found in the heavier-duty models.
To determine the specific engine size in your 2003 Chevrolet Express, you can:
* Check the vehicle's VIN (Vehicle Identification Number): The VIN contains information about the engine, including its size.
* Look for an engine sticker under the hood: The engine sticker usually provides the engine size and other details.
* Check the owner's manual: The owner's manual will also list the engine specifications.
Let me know if you have the VIN and I can help you identify the engine size.