3 valve or 4 valve heads
 

I have a 99 gt 5 speed- motor is all stock. Was just tossing a few things around in my head- what would the better of these two routes to take- swap out my heads and cams and intake with 4 valve heads cam, and intake or swap to a 3 valve head cam and intake set up? basically which set up would give me the most power. And if anyone could add anything i am missing parts wise that i would need. I work at a ford dealership so i get ford parts at a great discount so i do realize that their are other aftermarket bran heads and cams out their that may be a little better but $$ talks and i can really save a ton sticking with ford parts.
-heads
-cams
-intake
-tune
-fuel injectors?
-fuel pump?
- possibly new MAF

On a 4.6, there's no need to go anything better than 3V unless you need that high rpm edge. Personally, on the street, I think ported 2V heads are good enough since the 2V heads give you that low-end grunt that a street car needs.

what kind of gains do you think i would see from porting the heads? I would still think swapping heads and cams would give me a significant gain over porting the heads.

True but it's probably going to be cheaper since you don't need to buy new intake manifolds, exhaust manifolds/headers, etc. Also, the gains from porting combined w/ cams and headers are pretty substantial. Remember, it also depends on your application. Multivalve heads shine on top while 2V heads are great down low. Unless you are going to make sick power, the 2V will sit fine. Remember, the 281 is a small engine, it's not going to need tons of air unless you wind it up or boost it.

so ported heads combined with maybe comp stage 2 cams would probably give me a quite a noticable gain. well and a dyno tune also

It should give you a good bump.

I would agree unless your going to run some good boost threw it its not worth getting all the parts for the swap. The 2v will make sick power with the right parts and its more then enough for most people to handle.

Heads
 

I had a set of patriot stage 2 heads, assembled from them for 1400 shipped i think, and a set of stage 2 V/T N/A cams.... with a p-51 intake... and the normal bolt ons... and the sound was amazing, and the performance was pretty substantial over stock...

if your not going to boost, no need for more then a 2 valve...

i really liked that combo i had....

i would go big first before i start with everything else.

get a super charger and that will put you at 400 hp safely. then, as you go, build the block. up the boost. then, buy some ported heads and blower cams and you should have a pretty stout car. dont forget the transmission and rear end.

thats pretty much what i came up with as my best option- supercharge it. then eventually build it up.