[ModMustang97GT]

I would not stay withe NPI heads. Ported NPI heads put out numbers about the same as PI heads and Porting costs alot more than getting a set of used PI heads. The better flow and potential of the PI head greately out weighs the power and flow of the NPI especially when adding boost or Nitrous to the equation. As the power increases, that difference in efficiency gets bigger and bigger.

AS far as potential goes, there are people that have gotten these motors to over 400hp NA, but it costs alot of money and is not streetable.

Beating your friends car is going to take...
swap to some PI heads ($300)
Swap to Stage 2 Cams. ($500)
4.10 gears ($300)

Get more serious...
Vortech Super Charger kit ($3000)

End result, about 360-400 rwhp with a 1/4 mile in the 12's if you know how to drive and strip it down a little bit.

[the misfit wolfie]

Originally Posted by GMoney98 Those are the mods I have done except i didn't p/p my heads and they are pi. Once i get eveything done i will post a video for you to see if thats what you want to do.

sweet. id like to see it, i was playing with different ideas and dont know quite which way to go.

Originally Posted by ModMustang97GT I would not stay withe NPI heads. Ported NPI heads put out numbers about the same as PI heads and Porting costs alot more than getting a set of used PI heads. The better flow and potential of the PI head greately out weighs the power and flow of the NPI especially when adding boost or Nitrous to the equation. As the power increases, that difference in efficiency gets bigger and bigger.

i agree that you would see the same, if not more with the pi heads, but you would also be raising the compression ratio and that wouldnt be too good if you want to boost later on, sticking with ported npi heads just leaves you open for more options. but if he has no desire at all to boost or put nitrous in his car without working on the bottom end, then go for the pi heads.

[4.6LMadness]

You can safely run nitrous on a high compression motor. It doesn't bump your static compression ratio like boost does. You just need to retard the timing a bit and maintain proper full mixture to avoid detonation and your good to go.

[97stanggt]

5.4 with just stage 2 cams will run you 300hp about 330tq at the wheels... and alot more torque down low ied say a 5.4 swap spend 5k on it and forge the bottom end with some deeper dish pistons to keep compression low and then spend another 3000-4000 later on for a blower and put down some serious numbers and leave ur friend wanting more also ;> but unless he goes 5.4 also hell never keep up without some serious work

[mister0big]

hell ya that sounds good g money. ok here are my new questions

how much can i get a 5.4 for, does it have a forged block already?

if i rebuild my engine, should i keep any factory parts, and what are your recommendations for a block for the 4.6? and can it handle a supercharger if i put one on later? i dont think im going to put nitrous on it just a supercharger.

[the misfit wolfie]

Originally Posted by mister0big hell ya that sounds good g money. ok here are my new questions how much can i get a 5.4 for, does it have a forged block already? if i rebuild my engine, should i keep any factory parts, and what are your recommendations for a block for the 4.6? and can it handle a supercharger if i put one on later? i dont think im going to put nitrous on it just a supercharger.

for the engine it varies, some people here have gotten it for under 500, iv seen them for over 1000. go to car-parts.com you can look for the engine there. and if you rebuild your 4.6, it all depends what your going to do to it. stock, the engine can handle up to 9 or 10lbs of boost, which is still a fair amount of power. if your going to get block, forged is always good. expensive though.

or you could go with this, although its most likely over 5k,
Recipe for a 350 RWHP NA 2V

[ModMustang97GT]

So far, money wise, i have not seen the 5.4 make up the difference. Its a pain to get in the car and hooked up correctly, and with no good aftermarket headers. And no really well flowing 2v heads. The displacement difference is good, but not as good as it could be. I see lots of people with really nice set ups not putting down a real worth while difference.

Of course, I'm sure if you take the time to do it right, its worth it, and more power is definitely more power. I just don't think its worth the hassel, atleast not with a 2v motor.

As far as the forging goes, if you know how to wrench, you could do it your self for 1500 dollars and have a motor that is good to 700 hp. Throw a $4k super charger kit at it, and your at 500 rwhp easy. Now at that power level, you need some supporting mods in the rear end and some suspension. But with that much power, your basically a race car anyway.

I really think pointing him to the 5.4 swap is like pointing him at an 03-04 cobra engine, no doubt its cool, but its way to large an undertaking for his experience with this car, and the money he is talking about. Remember the golden rule. It always costs 50-100% more than you expect.


BTW, proper porting will help reduce how much the compression ratio goes up.

[97stanggt]

umm to get it in all i did was ground a nub off the pass side exhaust manifold.... and then 30min to get it on hoist in car and engine mounts bolted down....hows that hard? and about 1 1/2 hrs hooking back up ps pump ac pump accessories motor in to motor running was probaly 4 hrs work since i broke the oil filter adapter thats it ;> so whoever told u or if u think its hard to get in is idiotic in all sense of the word or is the worlds shittiest mechanic

[mister0big]

Originally Posted by ModMustang97GT So far, money wise, i have not seen the 5.4 make up the difference. Its a pain to get in the car and hooked up correctly, and with no good aftermarket headers. And no really well flowing 2v heads. The displacement difference is good, but not as good as it could be. I see lots of people with really nice set ups not putting down a real worth while difference. Of course, I'm sure if you take the time to do it right, its worth it, and more power is definitely more power. I just don't think its worth the hassel, atleast not with a 2v motor. As far as the forging goes, if you know how to wrench, you could do it your self for 1500 dollars and have a motor that is good to 700 hp. Throw a $4k super charger kit at it, and your at 500 rwhp easy. Now at that power level, you need some supporting mods in the rear end and some suspension. But with that much power, your basically a race car anyway. I really think pointing him to the 5.4 swap is like pointing him at an 03-04 cobra engine, no doubt its cool, but its way to large an undertaking for his experience with this car, and the money he is talking about. Remember the golden rule. It always costs 50-100% more than you expect. BTW, proper porting will help reduce how much the compression ratio goes up.

for 1500? how can that be done? i am pretty interested now as i only want to acheive 500-600 hp with a supercharger. is this what you have done to your mustang?


and also thanks everyone for the knowledge.

[97GT4.6]

Realistically,$1500 for forged internals is if you build it YOURSELF as stated (If you know how to wrench) so don't expect any less if your going to have someone build it for you... it can be done, but it will probably be more than that if you don't know how to build it.

[HBK_2007]

i could prolly rebulid a 4.6 block for 1500 but...by myself i wouldnt trust my handywork so id have to have someone (prolly my dad) help me so it would cost a bit more. i think mmr is having a sale on short blocks.

as for a 5.4 goes. if u have the motor already (or get a stupidly cheap deal on it) i wouldnt run it due to the fact u can get the same results hp wise and be that much lighter (lighter is faster, hp being the same) and i havent seen a 2v 5.4 thats been able to make up the difference in wieght in tq vs a alumium 2v 4.6.

Ford Racing Performance Parts [M-6010-GTWS*]
that bitch is a totally different story tho. if it didnt cost $4K id have one in a second and that would be the only way to go

[mister0big]

thanks again. my uncle has been a mechanic for 20 years he said he will help me rebuild it(meaning he does the work i watch and buy the beers) lol. so i am interested in the 1500 idea, what parts would that be, i have been looking at blocks but am unsure of were to buy online.

[50fanatic]

So with the PI top end, the 96-98 4.6 mustangs or 94-96 4.6 thunderbirds will make more power than the 1999-2004 mustangs?

[Regulator]

Correct, as the pistons they have along with the PI head yields a higher compression ratio