Wooo-Hooo Purchased a 4.6 GT

[85 Coupe 5.0]

Well, i went and did it, sold the '85 and bought a 1996 GT. Completely stock, never had anything done except regular oil changes and maintainence.

Since I am new to the 4.6 world, I have read a lot about the PI Heads/Intake swap, and from what I can tell it's the thing to do if you are looking for cheap upgrades. I have seen these heads go on E-Bay for $400.00 or so a set used, cams included.

My question, is the swap really worth that much? I see figures that say anywhere from 30HP to 60, which is it? Can anyone help me with some real world numbers here, more importantly, maybe some before/after 1/4 mile improvement times?

I am almost ready to purchase a set of heads, but would really like to know how much of a benefit they are over all, as it is quite time consuming to pull the motor down just for the swap.

Thanks!

 

[Barrier]

If youre looking for good gain for cheap $$... I'd go first with an X-pipe... the 94-04 stangs have 6 cats on the midpipe, extremely restrictive... but definitely those PI swaps I've heard are pretty good, but then again its second-hand info, I haven't done it myself.

 

[ACSPONY]

I have not done the PI swap either but some cars react better to the swap than others. You may net about 50/60 hp or you might be on the 30hp end

 

[85 Coupe 5.0]

I was really thinking about exhaust first, really really hard, as i had an off-road H-pipe on my old setup and 2.5" flowmaster cat back, and I really miss the sound.

I work at a Ford Dealership and have looked up all the specs on the differences from the cams from PI to non pi, and it seems like a real decent way to open up the earlier 4.6L's, but I am still unsure, thanks for the info so far tho.

Anyone else have any experiences?

 

[DropTopPony]

most of the guys that i know who have done it gain 40-50 rwhp, that not bad for 350 for heads and 110 for pi intake(thats what i paid just last week for my swap) you need a few other parts, gaskets, oil fill tube etc...and if you add aftermarket cams you can gain another 25rwhp...not to shabby...there are guys making over 300 rwhp with pi swap, cams, long tubes etc....and those who get the ported heads are doing even better. there is alot of potential in the swap.

 

[85 Coupe 5.0]

most of the guys that i know who have done it gain 40-50 rwhp, that not bad for 350 for heads and 110 for pi intake(thats what i paid just last week for my swap) you need a few other parts, gaskets, oil fill tube etc...and if you add aftermarket cams you can gain another 25rwhp...not to shabby...there are guys making over 300 rwhp with pi swap, cams, long tubes etc....and those who get the ported heads are doing even better. there is alot of potential in the swap.

Sounds great, i plan to do the swap eventually, but was unsure on what to do first, exhaust or the PI upgrade. Thanks for the advice!

 

[stangliter04]

one of my friends is doing the swap and I have looked up a lot of info on the swap not only will you see the 30-60 HP whatever you might get your other mods you might do you will see better gains from them as well. do the swap!

 

[1992 2.3LX]

if a blower is in your future i would not swap to the PI heads but just get your NPIs ported.

 

[Sick96Stang]

You want some real world #'s here ya go. I dynoed 212 rwhp 284 rwtq before port and polished PI heads/cams, PI intake, and shortie headers. Dynoed 243 rwhp 284 rwtq after those mods. I still think my #'s are really low for my mods, the port and polish isnt anything special just some buddies who know what they are doing did some port and polishing work on them. #1 Do the PI headswap asap before any other mod u even think about doing. It really wakes the car up top. If you want you can look at my cardomain link is in my sig. I have both my dyno graphs posted on there. You can see with the PI headswap it really wakes the car up after 3200 and up. The PI headswap is the foundation pretty much of doing other mods, all your other mods will be better because of the PI headswap. #2 As far as no blower with the PI swap I'm tired of people saying that **** and not explaining it. If you do the PI headswap then your compression will be to high to boost, perfect for nitrous though. That is because the 96-98 have flat top pistons and the 99+ have dished pistons. So if u want to boost its not impossible or anything just need some dished pistons. Might as well throw in some better rods while you are at it. If you port and polish the heads dont expect any real gains from them until you do some cams/blower. As far as horsepower goes with gains from the PI headswap I see mostly between 30-50 rwhp. Dont belive all that **** about 110 rwhp and other like that. If you got any other questions feel free to hit me up.

 

[Trick98GT]

Screw the H and X pipes...Get a PROCHAMBER.

If you can get your hands on a used PI motor, it's alot easier to swap than those heads, lol. Then again, you wont get the raised compression, but you'd still be runnin PI power.

 

[Sick96Stang]

Screw the H and X pipes...Get a PROCHAMBER.

If you can get your hands on a used PI motor, it's alot easier to swap than those heads, lol. Then again, you wont get the raised compression, but you'd still be runnin PI power.

I'm guessing your sig just isnt up to date but 310 rwhp 461 rwtq? I'm guessing you have 100 shot or so? BTW who cares what mid-pipe you get your gonna get the same performance gains out of all of them so just buy for whichever sound you like the best.

 

[csledd]

If youre looking for good gain for cheap $$... I'd go first with an X-pipe... the 94-04 stangs have 6 cats on the midpipe, extremely restrictive... but definitely those PI swaps I've heard are pretty good, but then again its second-hand info, I haven't done it myself.

my 03 only had 4 cats.. now it has 0


I would go with the swap on that car for sure!

 

[hognutz]

my .02 would be do the pi head swap with cams at the same time. or at least put some comp springs on the head so you could swap the cams in later without having to hassel with the spring swap.

 

[85 Coupe 5.0]

You want some real world #'s here ya go. I dynoed 212 rwhp 284 rwtq before port and polished PI heads/cams, PI intake, and shortie headers. Dynoed 243 rwhp 284 rwtq after those mods. I still think my #'s are really low for my mods, the port and polish isnt anything special just some buddies who know what they are doing did some port and polishing work on them. #1 Do the PI headswap asap before any other mod u even think about doing. It really wakes the car up top. If you want you can look at my cardomain link is in my sig. I have both my dyno graphs posted on there. You can see with the PI headswap it really wakes the car up after 3200 and up. The PI headswap is the foundation pretty much of doing other mods, all your other mods will be better because of the PI headswap. #2 As far as no blower with the PI swap I'm tired of people saying that **** and not explaining it. If you do the PI headswap then your compression will be to high to boost, perfect for nitrous though. That is because the 96-98 have flat top pistons and the 99+ have dished pistons. So if u want to boost its not impossible or anything just need some dished pistons. Might as well throw in some better rods while you are at it. If you port and polish the heads dont expect any real gains from them until you do some cams/blower. As far as horsepower goes with gains from the PI headswap I see mostly between 30-50 rwhp. Dont belive all that **** about 110 rwhp and other like that. If you got any other questions feel free to hit me up.

sounds like the PI swap is definately the 1st step in starting basic mods. The car is definately slow on the top end, everything after around 4G or higher just kinda slugs along. Thanks for all the help, i think i'm going to start looking for the swap parts.

 

[Sick96Stang]

sounds like the PI swap is definately the 1st step in starting basic mods. The car is definately slow on the top end, everything after around 4G or higher just kinda slugs along. Thanks for all the help, i think i'm going to start looking for the swap parts.

You dont be disappointed I go all the way up to 3-3.5K then mash it now because it pulls so damn hard up there. Warning though you will lose some low end torque. Even though my torque #'s were the same it moved up in the powerband.

 

[BlackenedSVT]

www.karkraft.com
and
www.parkwayfordga.com
both sell complete kits for the PI headswap (cams, heads and intake).

Parts can be found cheaper online elsewhere of course. But just a heads up

Congrats on the new car, and DEFINATELY get the PI headswap done!

 

[85 Coupe 5.0]

www.karkraft.com
and
www.parkwayfordga.com
both sell complete kits for the PI headswap (cams, heads and intake).

Parts can be found cheaper online elsewhere of course. But just a heads up

Congrats on the new car, and DEFINATELY get the PI headswap done!

Thanks, i have always wanted this body style, and i really love the 4.6, they seem like really good motors, see them come through work all the time, had a 5.4 the other day with 296,000 on it and still going.

 

[ragu1585]

directly after doin the swap, if that is what u decide on i would def. take the 2.73's/3.27's and replace them with 4.10s. By far the best thing ive done, i would never go under a 3.73 after feelin the 4.10s Car dyno'ed at 196.9 hp and 269.9 ft lbs torque with gears, tune, catback, xpipe, & CAI.

pics of dyno and car at http://www.cardomain.com/memberpage/813692

 

[Sick96Stang]

directly after doin the swap, if that is what u decide on i would def. take the 2.73's/3.27's and replace them with 4.10s. By far the best thing ive done, i would never go under a 3.73 after feelin the 4.10s Car dyno'ed at 196.9 hp and 269.9 ft lbs torque with gears, tune, catback, xpipe, & CAI.

pics of dyno and car at http://www.cardomain.com/memberpage/813692

Gears are a definite just make sure you can handle them. 4.10's are awesome but it will also make your car alot harder to launch. I would suggest doing some nice suspension/tires at the same time if not before. LCA's + DR's + 4.10's =