which head for the 4.6L?

[ac97gt]

which head is the best? barring money, whats my best bet. i want to make at least 300hp n/a when im "finished" but i also want to stay emissions legal. i have heard that AFR makes great heads and that the 185 is a good head, but i was reading a little and it seems like its for the 302-351 engine? or can you use it on the 4.6L engine. so which head is the "best" and what kind of horsepower increase can i expect from it. (or should i do intake first, i cant afford to do both at once unfortunately).

[95mustanggt]

While I don't know very much about aftermarket heads for the 4.6L (almost nil ). I do know that the AFR heads are not going to fit on your 4.6. Nor will any 302 or 351 head. You need an OHC head. I believe ford has one, but there must be a few more choices out there by now. Pick up a MM&FF and check the ads, there has to be someone in there that is selling them.

[COUSIN ROB]

I think the Bullit heads are a popular choice. Don't know for sure but I am quite sure I have seen them mentioned before. Do a search and check them out.

[Hammer]

The best flow numbers (stock) for an aftermarket OHC head are the ford motorsport pieces... very nice and very expensive...

[Los]

Originally posted by COUSIN ROB
I think the Bullit heads are a popular choice. Don't know for sure but I am quite sure I have seen them mentioned before. Do a search and check them out.

The Bullitt head is the same head as a GT (99+ PI heads). The only difference motorwise is the intake. You can't get aftermarket heads, at least, not in the sense as a $1200 dollar package deal. You can send your heads off to different shops like Port Pros in Austin Texas or Lake Fox (Or was it Fox lake?) for an undisclosed amount of money to get your heads ported. Its best to do it with 99+ PI heads because of the already increased amount of power in basic form.

[ac97gt]

Los - so are you sayin i cant spend $1200+ and get aftermarket heads?

Hammer - yeah i read on some websites about the FMS heads... i noticed they have good numbers and are $$, but i guess i have it stuck in my head that if its still ford, its not "aftermarket" and couldnt be as good as other brands, stupid thinking but thats just what registers when i hear it. when you said that they have the best flow numbers (stock) you meant without being ported etc. right? can you buy aftermarket heads that are already ported or anything? i mean, why would you buy aftermarket heads then have to have them ported again, you would think it would already be the best that it could be. sorry if that is a stupid question but i dont know much about this.

thanks for your help.. anyone have any experience with different heads on their 4.6L or are you all using stock and ported or 99+ and ported?

[Badass_yellowGT]

just buy th head swap kit it makes decent power increase and the engines will be rated at about 275 if your still stock. well worth the 1200.00 kit

[ac97gt]

which kit are you talking about, exactly Badass_yellowGT? so that kit adds about 60hp? 215 stock to 275? thats a pretty good increase, more than i would have guessed. would you suggest this kit over some FMS heads?

[Hammer]

The 99 PI heads\intake swap gives a good power increase for a decent amount of miney. It is also not a direct "bolt-on" and minor changes to your setup have to be made. Bad news is that compression is increased and its not to friendly if planning on going forced induction.

The Ford Motorsport Cylinder heads flow better (more horsepower) and compression ratios are much more favorable if you go to forced induction (blower). Bad news is they're quite expensive...

when you said that they have the best flow numbers (stock) you meant without being ported etc. right?

Correct

can you buy aftermarket heads that are already ported or anything?

You can buy the 99+ PI heads and port them. I've also heard of some folks even porting the FMS pieces....

In my opinion, if money is no object, the route to go is the FMS heads\intake combo. It's almost a straight "bolt-on" affair, gives great power numbers, and is ready for a blower when you are.

My old 98 with that setup made 385 hp at the rear wheels with about 6.5 lbs. of boost present at the intake (8 lb. pulley)from the blower. This was with a conservative tune keeping the timing down.
Over 400 rwhp would have easily been attainable with a more aggressive tune and a 10 lb. pulley.

[ac97gt]

thanks, you're response is just what i wanted to hear. i do plan on going for a blower eventually *if* i ever get the money. i might have a new car by then, but i do want to set it up right in case i ever want to. the FMS intake/heads sound good. like i said i can only get one or the other then save and get the other, i wanted to get heads first but should i get intake first? what kind of hp numbers can i expect to add with just heads? with just intake? with both?

[surfbeast]

The best bet for the 97 gt's is the FMS heads, the FMS intake or the FMS screw type blower wich replaces the intake. These are costly but will work best with the engine and other components. No real aftermaket heads are available, only ported 99 PI heads. FRPP has a set of heads for the 96-98's for about 750.00 bucks that I saw on the GEF racing site. Don't quote me on that price!

[stangt00]

Actually there are more than just the FMS heads out there. Sean Hyland Motorsports makes one. I am about to get my PI heads ported/polished/valved with comp cams and springs. I will post back with dyno #s after the work, but I was told I should see no less than 300 at the wheels.

[playahata]

Originally posted by surfbeast
The best bet for the 97 gt's is the FMS heads, the FMS intake or the FMS screw type blower wich replaces the intake. These are costly but will work best with the engine and other components.

To clarify, you can run the FRPP heads and intake OR the FRPP blower on your stock heads. The blower won't match up to the FRPP heads without some machine work.

[playahata]

Originally posted by stangt00
Actually there are more than just the FMS heads out there. Sean Hyland Motorsports makes one.

There are two sets of heads available for the SOHC 4.6, the FRPP or the PI. Sean Hyland just ports and valves the PI heads, they aren't an "aftermarket" design.

[stangt00]

Sean Hyland just ports and valves the PI heads, they aren't an "aftermarket" design.

Does it make a difference what head he uses? No! His company sells an aftermarket set of heads. Regardless of what the original piece may be, they are still better flowing PI heads. It is an option to buy vs the FRPP heads at a much lower price. The original question here was what head could he buy to replace his stock NON PI heads. I gave him a cheaper alternative to the pricey FRPP

[Los]

Yes but they're not like "AFRs" or Trickflows. They're the same mill PI heads found in any 99+ GT, ported and whatever else and sold at a high price. You'd be better off sending them to a place to get it done yourself.

But SHM and most of the other aftermarket support groups sell great heads.

[playahata]

Originally posted by stangt00
Does it make a difference what head he uses? No! His company sells an aftermarket set of heads. Regardless of what the original piece may be, they are still better flowing PI heads.

They may be a better option than his stock heads, but the PI and FRPP heads, ported or not, are NOT aftermarket heads. They are designed and manufactured by Ford, period.

[Hammer]

I don't know about anybody else, but I think AC97's question had to do with a performance increase, not what the term "after-market" meant....

I couldn't care less who makes it. Ford, Trick-Flow, SHM, or God himself...

The determination of what goes into my car is based on two factors: price and performance.

[stangt00]

I couldn't care less who makes it. Ford, Trick-Flow, SHM, or God himself...

I like that reply. Maybe the term Aftermarket was not appropriate, but the point is still the same.

ported and whatever else and sold at a high price. You'd be better off sending them to a place to get it done yourself.

Are you referring to AC97's factory heads?

[ac97gt]

thanks for your replies. i was just curious what is out there. im actually surprised to hear there really arent many options, i thought there would be alot. it sounds like the FMS heads are my best bet.. do they make more than one model, if so which is the one that i would want? what kind of numbers can i expect on an otherwise stock engine?