* 6.0L Power Stroke V8 Turbo Diesel: This was a common choice.
* 5.4L Triton V8 Gasoline: A gasoline option.
* 7.3L Power Stroke V8 Turbo Diesel: This was offered in some early 2003 models but was phased out during the year in favor of the 6.0L.
Therefore, there's no single answer to your question. You need to specify which engine was in the particular truck you're interested in.