How can you tell if your truck has them or not ?

 

There is a sticker on the drivers side valve cover that will say PI for power inproved. It's also stamped on the head somewhere.

 

The casting on the head is difficult to see, you sort of need to crawl under the truck, and look along the bottom of the head. with a flashlight, the letters PI will be cast into the head, if they are PI heads. What year is your Expedition? Some of the 99's, apparently didn't get the PI head until very late in the production year. Mine which has a Mfg date of January 99, engine Mfg date of December 98, does have the PI's. There doesn't seem to be an explaination, at least not one that I have heard.

 

mine is a 2000 5.4.

 

Your 2000 should have the PI heads!

 

The sticker on the valve cover may or may not have the "PI" don't rely on that decal. If you really want to know, you need to check that casting number on the head.