ok my brain is hurting and im tired of reading. been searching and reading for awhile.

i have a 98 4.6. what i want to do is swap to pi heads. now are all pi heads created equal and will head from 5.4 fit 4.6 and vice versa.

i can get a 5.4 out of a 2003 for around 200 bucks. what all will i need off of this motor before i go and look at it. that is if it will work.

also what will it do to my mileage, not that im concerned about it, just wondering.

 

The heads. So you already have a PI intake then? You'll need one from an 01 plus 4.6L.

 

I don't think they will interchange wothout any issue because 03 5.4 intake gasket is different from 4.6 in 00 and 01 up. They share the same intake gasket on 97-99.

No huge gain using PI Intake on Coil Pack Ignition. Upgrade your Ignition to COP to gain more performance and better mileage.

 

the motor is still in the truck so i can grab anything i need from it, if it will work.

i can get the whole motor for 200 bucks. i think thats a deal, although i will have the heads reworked anyway.

 

All I can do is tell you what you need. Looks like it went way over you head.

Well, - you'll find out the hard way.

I'll say it one more time, maybe your just not putting the words together right. YOU NEED a 4.6L PI intake. Your engine doesn't have one, - the 03 5four doesn't have one to fit your engine.

How else can I explain, - the 4six isn't as wide as the 5four on top. That's why a 5four intake won't work on a 4six block.

 

Ok here is the skinny. You need a 01 and up 4.6 intake from an f150 or expedition. You will also need any pi heads from a 4.6 or 5.4. They will bolt right up using pi head and intake gaskets.

To get the most out of the swap you will need a custom tune though.

 

Well, he will need to find a intake and new intake gaskets specific to PI intake he finds. That because Ford changed locator pins (dowels) around from model year to model year.
EDIT: It's specific upon whether the intake is plastic or metal. I think they are the same gasket regardless. Ford thickened up one side of the gaskets for certain model years. Well , it's screwy stuff like that, that happened in the past which makes Ford the only go to for those gaskets.

COP,s or Coil Pacs, doesn't matter. He can keep his Pacs because it's the thing to do since there's absolutely no difference. If he wanted to change for whatever reason, he would need to modify the PCM and coil drivers. Doesn't make sense to do that. Hell , there engines pushing 1000 hp using coil pacs.

For mileage, that will fall into place (best it can be) once the engine is custom tuned for the set up. If it were me, before tuning I would add e-fans, a straight through air intake (dry element only) and LT headers. Bring all that in for a dyno tune and that little 4six will turn out pretty good.

 

Yea, already said that.

 

So, what you have to do, just like I said earlier and jprevats skinny (same thing).

In summery, -

1. Get the heads, you'll need gaskets.
2. You'll need to find an intake , - 01 plus from a 4six.
3. You'll need intake gaskets. This is very important, purchase new intake gaskets from Ford ONLY. No where else. There's many revisions to those gaskets and 3rd party hasn't kept up with that.

 

ok i see what you were saying now about the 4.6 intake.

i might as well look for a 4.6 like i found the 5.4 and then ill have all the parts needed right? there is no difference on the heads from either?

also how do they custom tune a 98?