Because the exact location can be subtle, it's best to:
* Consult a repair manual: A Haynes or Chilton manual specific to your year and engine will have a diagram showing the PCV valve location precisely.
* Use an online parts diagram: Many auto parts websites (like AutoZone, Advance Auto Parts, etc.) allow you to look up parts diagrams for your specific vehicle. Searching for "1989 Toyota Pickup 3.0L V6 PCV valve" will likely yield a diagram.
Without a visual aid, pinpointing its exact position is difficult. Checking these resources will give you the most accurate information.