My buddy wants to make his 00 GT fast. He wants to stay naturally aspirated. He wants to prove his LS1 friend wrong .. his LS1 friend says that 4.6Ls can't be fast, even with my mods. I have another friend with a 97 Cobra who has the same dilemna. I don't own a Mustang, so I was hoping you guys could give me some direction. :-D

Performance chip, CAI, Bullitt intake, mass air meter, pulley, fuel injectors, heads, cams, headers, cat back, gears, drag radials, and big bucks.

what is he looking to spend?

sure he can get a port and polish, new intake, cams etc. but can he afford it?

If you're on a budget like most of us, look into drag radials for traction, some 3.73 or 4.10 gears, pulleys, plenum,timing adjustor or custom tune, simple things like that.

Bang for the buck, pulleys, gears (4.10), intake, exhaust. All are somewhat inexpensive and help.

when you say intake, do you mean plenum?

because i dn't think $1600+ for a bullit intake is a good bang for the buck.

MAC cold air intake.

Here is the list of mods I would do on a 99+ 4.6L GT. Lets assume 5-speed since it wasnt listed.

Bolt-On's: Power Group
Steeda Underdrive pullies
C&L trueflow inlet pipe
Accufab upper plenum
Accufab 70mm TB
Dr. Gas X-pipe
Magnaflow cat-back

Bolt On's: suspension/drivetrain group
4.10 Gears
Upper and lower control arms
Subframe connectors.
Drag Radial's (nitto's if used on street much, BFG's if used at track mainly).
steeda Tri-Ax shifter.

The above should put you in the mid 13's easy at the track, given you can feather your clutch enough to not let it bog, but also not let it spin.

If you want to take it a step further and really show the ls1 what a 4.6 can do:

Get a set of cams, I recommend http://www.VTEngines.com they make awesome cams.
Look into a set of Ported and polished heads.
Get a good custom dyno tune for the car. my choice is http://www.superchipscustom.com

If you do that, learn how to launch the car, 12's are not going to be a problem. Throw a set of slicks on and mid-12's shouldnt be to hard.

If you're like most 4.6 guys just get a supercharger LOL (j/k guys). I'm planning on N/A myself and it's going to be rough. Getting the simple bolt-ons is the easiest way to start, then get into the suspension (just research for what you're looking for..only you know what you want). After that then as the others said, go cough up the big bucks for your heads and cams....that should give you some pleasing results. Just remember that all in all...we've still got just 4.6 liters hehehe...but wonders can happen.