To be certain, you should:
* Consult your vehicle's repair manual: This will have diagrams and specific instructions for your exact model.
* Use an online parts diagram: Many auto parts websites (like AutoZone, Advance Auto Parts, etc.) allow you to select your vehicle's year, make, and model and view diagrams showing the location of parts.
Without knowing the specific engine, it's difficult to give a more precise location. Using one of the resources mentioned above will ensure you find the correct position on your van.