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Discussion Starter #1
Got a line on pair. I'm wondering what kind of gains I could expect out of them. And if porting them will make a big enough differance to make it worthwhile. And before someone calls me a dumbass, I really don't have much experiance with the 4.6, all I have owned up to htis point has been a few SC's.
 

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Discussion Starter #3
On the Vic in my sig with the NPI intake for now. Fitment isn't the issue, as I am getting them from a guy who just took them off his car.
 

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Baddest N/A NPI in Canada
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The SVO heads flow 215 CFM on the intake side stock, that is where most stage 2 P&P heads flow and you need a stage 3 job to beat that! Stock NPI and PI heads flow around 170 CFM stock, I don't remember the exact number. However P&P SVO heads flow around 250 CFM on the intake side when P&P.

How much are you paying for these?
 

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Discussion Starter #5
A very good price. I'll wait till the transaction goies through and I talk to the seller before I post that.
 

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the 5.4l heads are the same as the 4.6 heads npi and pi
 

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well if you put pi heads on a 4.6l npi block you need to get a chip. but if you put 5.4l heads from a 97 or a 98 5.4l on your 96-98 NPI block you won't need a chip because they are the same exact heads.
 

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Maybe you are looking at the 4.6/5.4 PI heads, those are different than the ones you have.

To the best of my knoweledge there are 3 tupes of 2V head for your cars.

92-95 NPI - Supposedly the worst, but in my experiences unported they are close to the 96-98

96-?00? NPI - 4.6/5.4 used on the mustangs til 98, tbirds/cougars until 97, f150's, crown vics, vans...

99+ PI for 4.6/5.4 These flow better than the above heads, and have different cams; you would need a different intake manifold and if you have a 92-95 4.6 engine there are other parts you need to make it work.

You would need a chip to maximize your performance if you are going to put PI heads on an npi engine.

-Andrey
 

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91-95 FE4 casting the suck butt heads

96-98 FE5 casting thats the one we got on stock 96-97 birds

the 99 ups are all pi's not sure on the casting number

you dont need a chip with the upped compression from the pi's but its a very smart idea to get one as 9.4 to 1 vs 10 to one is a big diffrence

svo heads on the vic will gain you ALOT b/c of the vics stock FE4 casting heads

but your sticking with the stock aluminum intake witch is a big restriction, but you will still gain power, just not as much as you could by going with a better intake

5.4 and 4.6 heads are the same, 5.4s dont come in an FE4 casting head, meaning they only were around for the npi's that we use that name for (FE5 casting heads) and the pi's
 

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JoeyICU said:
91-95 FE4 casting the suck butt heads
That's what I thought too, then I ran against Tony (see racing) and my mind has changed. I think its more of a untested rumor that is getting spread. Now, I am saying stock unported, I have no experience with ported heads.

-Andrey
 

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They are the worst for porting. If you have a choice it is strongly recommended to use the ladder (96-up) casting.

Stock I would imagine that they are not very far behind the 96 and up casting.

Good luck with your purchase Stubbs. Cant wait to see what you've bought. :cool:
 

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Real Ultimate Goatse Hunter
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MadRussian said:


That's what I thought too, then I ran against Tony (see racing) and my mind has changed. I think its more of a untested rumor that is getting spread. Now, I am saying stock unported, I have no experience with ported heads.

-Andrey
Rumor? Maybe to people who don't look into this kind of stuff. I think alot of us have seen the proof for ourselves in the actual head to prove otherwise,
 

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NRL said:

Rumor? Maybe to people who don't look into this kind of stuff.
Well, thats exactly what it looked like to me. Look at the time slips in "St. Louis visit" thread in racing.

Our cars are very similar, and according to bench racing done here my car should be faster too. I have a PI intake. Tony's engine is stock minus a RichardM tube and underdrive pulleys. Yet we perform almost identical.

If Tony's heads couldnt flow close to my heads he would have had lower times, and more importantly significantly lower MPH since MPH is the closest numeber to measuring horsepower on a time slip.

Again, this is a comparison between stock unported heads.

-Andrey
 

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the 94-95 heads also have poor hardware that needs to be upgraded to accomodate a small change like going to pi cams..
 

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yes the 94-95 heads are ill equiped, tony has a good bit of mods and hes only runing a tenth faster, some engines are more well endowed then other engines, bottom line 94-95 heads are terrible, and he may have more of the right mods then you do, something along those lines
 

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No, we have pretty much the same mods...

He has underdrives and full exhaust on me; I have PI intake, 02 GT MAF, and a crappy catback exhaust on him.

Everything else is about the same.

If in stock form the 92-95 heads were terrible then I sould be faster... but I'm not.

-Andrey
 

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Real Ultimate Goatse Hunter
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MadRussian said:


Well, thats exactly what it looked like to me. Look at the time slips in "St. Louis visit" thread in racing.

Our cars are very similar, and according to bench racing done here my car should be faster too. I have a PI intake. Tony's engine is stock minus a RichardM tube and underdrive pulleys. Yet we perform almost identical.

If Tony's heads couldnt flow close to my heads he would have had lower times, and more importantly significantly lower MPH since MPH is the closest numeber to measuring horsepower on a time slip.

Again, this is a comparison between stock unported heads.

-Andrey
I think its quite clear that the heads can't flow enough air if they arn't being fed enough air.
 
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