I have a 97 f250 ld (7 lug model) it has been my baby for 9 years. Rockstar 2s, new trans 2 years ago, rebuilt ecm, New radio, brand new tires, and rebuilt from valley up last year. I didn't catch it in time but block needs replaced now yay me. However before I spend the money on a new block I need to know if I can go to a pi block and heads without having to get a new wiring harness as I spent 1200 getting it fixed a few years ago. I just figured while I got to put a motor in it might as well get the extra 50+ ratings from the pi heads. New block going in I think unless it'd be a issue putting my new stuff on it. Sensors, intake, coils, alternator water pump thermostat and belt r all less then 2 years old. ik the seals won't matter. But any advice or clarification would be greatly appreciated!

 

There are four big differences between the engines. The PI engine has a coil per cylinder and the NPI has a coil box and wires for those years. (They make a crossover harness adapter for this type of change).
The PI engine does not have a butterfly valve on the lower part of the intake. The intake is different on a PI engine. (Here you just don't plug the harness in and tape off the plug).
The PI engine has a water/head temperature sensor in the right head facing the engine just under the intake and does not use the NPI temp system. (The NPI engine has a different hookup system for water/temp).
The knock sensor has a different plugin end on an NPI engine than a PI engine and you have to use your knock sensor from the NPI engine if you use your old wiring harness. (The knock sensor is the cable (cable only) that is on the left side facing the engine running back to the back of the engine in the valley under the intake).
The exhaust manifolds are different as well where they hookup to the tailpipe and bend. (If I remember correctly on this).

Overall it is easier to just get a new wiring harness for this changeover unless you have done this before.
Most junkyards get around less than $100.00 for a good wiring harness for a PI type engine. They are plug and play harness, just plug them into your main harness where the other one was plugged into.

 

Well I thought I was I different for another reason I guess somewhere along the way someone already did this swap cause I have coil over plugs already. I thought it was just one more thing different on the 7700 package...thank you for the information im gonna start hunting up a block. Tho I don't understand how all my other accessories fit a newer block but ill run with this information. So I'm guessing a 2003 block and heads would be best then right? Long threads for plugs?

 

You have the 5.4 2v engine and I was saying overall that the NPI had a coil block and not a coil on plug. Sorry for that.
1999 5.4L 2v was the first year of the PI engines and yes 2003 did fix a lot of stuff on the engines.
Just remember to change your flywheel if the engine you get came out of anything other than an F250 as they used a different transmission. (the E40D trans sets away more and bigger and the flywheel is thicker than a 4R70/4R75 trans flywheel).
You do know that they made the 5.4L 2v even up to 2010 for the e-van? Same engine overall.

If you have an engine with an EGR valve you have to get one the same. All of the other stuff will fit, like AC, water pump, fan, vacuum lines. The intake part is taller and bigger than an NPI intake and the holes in the intake that go over the heads are larger. Everything else is basically the same except the pistons are different in some of the 5.4 2v engines.

 

Thats what I kinda figured cause a buddy took a 98 expedition 5 4l and installed it in his 2002 f250 so I knew it could be done just wasn't 100% of the pc system thru the years but ill start looking for a 2v then I don't think mines has the egr valve tho

 

I don't wanna derail OP's thread but the Econoline went thru '14 IIRC and they were 2V all the way, no?

Not trying to argue, just clarify info for potential engine donors for others in the future

 

I could not remember what year they stopped making those engines for the Econoline van.
And you are correct about them being 2v and not 3v engines. I saw 2008 I want to say was an STX F150 that had a 4.6 2v in it and I thought all of them would have been 3v engines. That or someone put one in it.