Over 15 years ago I bought a set of Ford Motorsports headers for (then) my '98 F150 4.6. I never installed them and 8 years ago the truck got totalled anyway. Still have the headers. Now I have this '01 Expedition 5.4 (2V). My question is, will these headers fit the Expy? If they will, I'll slap them on. Been hanging on the wall in my shop for the whole time. Thanks.

 

No. 4.6 non-PI and 5.4 PI have different heads.

 

Shoot! Oh well. Anybody wanna make me a deal on a set of like-new, unused 4.6 headers? I should remember but don't, what does "PI" stand for? I also have an '05 Merc Mountaineer AWD 4.6; would they fit it? Thanks.

 

PI is "performance improved". 5.4 went PI in 99, 4.6 went PI in 01. They won't fit on the Mountaineer, I don't think anyone makes headers for it.

 

On my Mountaineer, do I have the 2V or 3V 4.6? I've heard that '05 is when the 4.6 went to 3V. However, the engine code on my Merc is a "W", which used to denote the Romeo 2V. Thanks.

 

The switch to the 3v was sometime during 2005, so if you have VIN W, you do have the 2v.