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PI Headswap Write-Up

  • Thread starter Thread starter 5spd GT
  • Start date Start date Aug 26, 2007
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Winters98GT

Whoop...whoop-whoop-whoop-whoop...GANGNAM STYLE!!!
Founding Member
Nov 29, 1999
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H Town
Nov 9, 2008
#21
  • Nov 9, 2008
  • #21
97ponygt said:
When I look up these parts quite a few of them are for f150's. Put it also says 4.6l in the description but never says anything about Mustang. What's that all about?
Click to expand...

it's all about "modular"

Parts based on a single design, so many of them are interchangable. The 4.6 was not designed for the mustang or to be a performance based motor, but as a modular design used in many vehicles.
 

pilks

Member
Jul 15, 2004
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16
Jun 22, 2010
#22
  • Jun 22, 2010
  • #22
i know its ancient but the link for PI Headswap Pictures doesnt seem to work for me..... fyi
 

Fobra281

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Jun 22, 2010
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#23
  • Jun 22, 2010
  • #23
I have a Romeo block ( npi) and Im putting Windsor heads on it (pi) so which head bolts do I use?
 

N8Dogg98

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Jun 22, 2010
#24
  • Jun 22, 2010
  • #24
Fobra281 said:
I have a Romeo block ( npi) and Im putting Windsor heads on it (pi) so which head bolts do I use?
Click to expand...

According to the write up you need windsor head bolts.

Part number: 3L3Z-6065-AA - (20 bolts)
 
T

tom70

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Jun 20, 2010
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Pa
Jun 22, 2010
#25
  • Jun 22, 2010
  • #25
great thread!!
 

Fobra281

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Jun 22, 2010
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#26
  • Jun 22, 2010
  • #26
N8Dogg98 said:
According to the write up you need windsor head bolts.

Part number: 3L3Z-6065-AA - (20 bolts)
Click to expand...

Thanks Im just triple checking at this point. Because someone told me Windsor head bolts wont work with a Romeo block.
 

N8Dogg98

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Apr 4, 2005
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Jun 22, 2010
#27
  • Jun 22, 2010
  • #27
Fobra281 said:
Thanks Im just triple checking at this point. Because someone told me Windsor head bolts wont work with a Romeo block.
Click to expand...

Haven't done it myself, but the write up clearly states that if you are installing windsor heads on the 96-98 stang (which is a romeo block) you need windsor headbolts.
 

Fobra281

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Jun 22, 2010
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#28
  • Jun 22, 2010
  • #28
N8Dogg98 said:
Haven't done it myself, but the write up clearly states that if you are installing windsor heads on the 96-98 stang (which is a romeo block) you need windsor headbolts.
Click to expand...

That was my exact statement to the person that said that to me. Im going with the write-up. I cant wait !!!
 
T

thyreaper

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Jun 11, 2011
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#29
  • Jun 11, 2011
  • #29
uhh valve cover problems

i just got a set of pi heads and i took them to the machine shop and they came back that they are from a 01-04 mustang 4.6l but i counted the valve cover bolts and i only came up with 9 on each head, my stock seems to have like 10-12 cant really see too much stuff in way, but ya the heads i got seem to only have 9 on top where the valve cover sits unless im missing one somewhere that i didnt see, whats this about?
 
T

thyreaper

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#30
  • Jun 15, 2011
  • #30
lol no one knows? im counting the ones only on the top, are there any on the sides or anything that i dont see? i looked at some pics online and i counted 9 on those to so im sure im not counting right
 
S

Sunset

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Sep 25, 2011
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#31
  • Sep 25, 2011
  • #31
thyreaper said:
i just got a set of pi heads and i took them to the machine shop and they came back that they are from a 01-04 mustang 4.6l but i counted the valve cover bolts and i only came up with 9 on each head, my stock seems to have like 10-12 cant really see too much stuff in way, but ya the heads i got seem to only have 9 on top where the valve cover sits unless im missing one somewhere that i didnt see, whats this about?
Click to expand...


1999 and and most 2000 Mustangs have Windsor based engines and 2001-2004 have Romeo based engines. Windsor had 12 bolts holding the valve covers and press fitted cam gears. The Romeo engines had 9 bolts holding the valve covers and bolt on cam gears as did the 96-98 Romeo Non-PI engines. Hope this helps.
 

5spd GT

"the 5.0 owns all"
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Sep 27, 2011
#32
  • Sep 27, 2011
  • #32
Sunset said:
1999 and and most 2000 Mustangs have Windsor based engines and 2001-2004 have Romeo based engines. Windsor had 12 bolts holding the valve covers and press fitted cam gears. The Romeo engines had 9 bolts holding the valve covers and bolt on cam gears as did the 96-98 Romeo Non-PI engines. Hope this helps.
Click to expand...

 

5spd GT

"the 5.0 owns all"
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Nov 29, 2011
#33
  • Nov 29, 2011
  • #33
I went to the track a few years ago, after completing my PI Headswap and thought I would post up the results (untuned - just bolted on) from the PI Headswap.

Before with Bone Stock NPI 1998 GT (5spd - 3.27 gears - 110k):

2.356 - 60 ft.
6.332 - 330 ft.
9.647 - 1/8 ET
74.89 - 1/8 MPH
12.30 - 1000 ft. ET
85.32 - 1000 ft. MPH

After with 2002 PI Heads/Cams/Intake (5spd - 3.27 gears - 133k):

2.159 - 60 ft.
6.032 - 330 ft.
9.255 - 1/8 ET
76.98 - 1/8 MPH
11.82 - 1000 ft. ET
88.15 - 1000 ft. MPH

Difference of:

.197 - 60 ft.
.300 - 330 ft.
.392 - 1/8 ET
2.09 - 1/8 ET
4.80 - 1000 ft. ET
2.83 - 1000 ft. MPH

Same track, similar conditions, untuned. This gives a ballpark of what you can expect to gain with a NPI to PI Headswap.
 
T

thyreaper

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Jun 11, 2011
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Dec 2, 2011
#34
  • Dec 2, 2011
  • #34
the info did help, the heads i have im guessing are romeo which means i can use my valve coverfs and all... they have removable cam gears on them to so im hoping the cams are stock.... im thinking of getting some adjustable cam gears so i can advance them 5 degrees or will it not make much of a difference? and what would that be in 1/4 mile before and after? with no tune
 
T

Thomas Camp

New Member
Apr 13, 2020
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Albertville,Alabama
May 1, 2020
#35
  • May 1, 2020
  • #35
I have a question if somebody can help me i have a 96 mustang gt and going by the #8 letter on the vin indicates that my engine is a windsor 4.6 but they only used romeo nonpis in the 96 gts right? Im confused hell both of my 96 gts have a windsor according to the vin
 

COramprat

...I can take it. I think.
20+ Year Stangneter
Mar 2, 2003
8,474
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Sea of Tranquility
May 3, 2020
#36
  • May 3, 2020
  • #36
What letter is the 8th letter?
 
T

Thomas Camp

New Member
Apr 13, 2020
11
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Albertville,Alabama
May 4, 2020
#37
  • May 4, 2020
  • #37
Its an x on both motors
 
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