I have been reading the past few days about PI heads, and intake. I have a 98, 4.6, vin W. Non PI motor. I've read that if you put PI heads, and intake on a non PI motor, it is a big HP increase.

So anyway, my local junkyard charges $38 a head. Is it just as simple as pulling, and cleaning them up and swapping them to my motor? Minus the manifold studs breaking.

 

thats about it my man! ive done my fair share of reading as well, its about 100 HP from all the mustang forums ive read... you could wake it up even more with a mild cam swap, LT headers and if you could ever find a wrecked mustang BULLITT, grab that intake manifold too, it nets about 20hp.... but, correct me if im wrong, im no expert

 

I'm no expert either, but I recall the PI heads only being worth like 20HP or so on the trucks. I think 100 is pretty wild. And I also want to say that the PI heads on a non-PI motor bumps the compression a lot, too much sometimes.

Well I looked it up and it bumps the compression to 10.5:1 (which IS pretty high) and you need a custom tune too. And you need the valve covers in addition to the intake. https://www.f150online.com/forums/v8...s-windsor.html

How much reading have you done? I don't want to insult you by telling you stuff you already know.

 

No youre fine, I can use all the info I can get. Would I be able to run the same spark plugs that are my truck now, or are the threads different?

 

Spark plugs are the same.

 

pretty sure PI motors have a larger dish in the piston so if you just swap the heads you end up with a higher then designed compression ratio. Custome tune and perhaps premium fuel will be required..

 

well, i stand corrected.... the swap can get you up to about 100rwhp if you do it with a few bells and whistles (intake, cams, porting, and headers) there's a ton of great info on most of the mustang forums since that is a common swap with them and not the truck crowd... here's another useful link

http://www.moddedmustangs.com/forums...npi-vs-pi.html

 

That sounds more like it haha. Those goodies can add that kind of power without the PI heads too Those are still good gains though!

It certainly seems that the intake, cams, and NOT the heads is the way to go. Great find, even if it was "copy and paste"

 

You say intake and cams, what particular intake are you talking about?

 

a bullitt GT mustang intake. you will loose torque, but gain HP. Your compression is a sure jump, dont reuse your NPI cams, the PI cams are better.

 

So will that Bullitt intake work with my NPI heads? and if it does, use the Bullitt intake, and PI cams on my NPI motor?

 

heres a thread on how to get a PI intake manifold to fit on the NPI heads, same should go for the bullitt intake, good luck finding a cheap bullit intake and be sure it comes with the throttle cable and throttle body and all the hardware...http://mustangforums.com/forum/4-6l-...npi-heads.html

 

Yeah I don't really know about a Bullitt intake. It's going to be so hard to find one used.

 

i have a set of PI heads with comp cam springs/retainers and stock valves that i bought on craigslist, the PO did a crappy garage P&P and the forward passenger cam journal is worn from low oil pressure but i had them checked out at my friends shop and he said he's seen worse. so they are useable... i was gonna do some top end work but i think im just gonna build a remote turbo setup for it soon... im gonna resell them for what i paid $140 + shipping if u want them... the comp springs are like $220 so not a bad deal if youre interested

 

okay, what cams should I run? Just pi?