Resonator box and air silencer?

[The Abyss]

Is there anything else I can do that's cheap or free?

[OH3MGSVT]

Is there anything else I can do that's cheap or free?

As for as best bang for the buck mods, I say go with some gears (4.10's or higher) 4v's love to rev and gears really wake them up. Mach's are pretty nasty with some gears in them (as far as N/A 4v's go) but the most common mods I see on Mach's are:

Meziere electirc water pump
PHP Intake Spacer

You may also want to look into exhaust options as well because mach's have pretty restrictive exhausts which isn't good for a free-breathing 4v. That should also wake it up some, I noticed a SOTP difference when I put my exhaust on (bbk o/r x and magnaflow magnapacks) and thats for a otherwise stock 2v GT.

P.S. STAY AWAY FOR UNDERDRIVE PULLIES! I hear that mach's have oil pump problems when they have U/D pullies on.

[The Abyss]

I'd love to get my exhaust done but I can't decide what to go with. I want to do everything from the headers back. I want my car to sound like this.

YouTube - Saleen mustang twin turbo over 900 rwhp!!!

[OH3MGSVT]

I'd love to get my exhaust done but I can't decide what to go with. I want to do everything from the headers back. I want my car to sound like this.

http://www.youtube.com/watch?v=BWx-XeaNMaY

ah dude thats like my favorite mustang video of all time! lol funny that you chose that. yeah I looked up the specs on the car and he has a full custom exhaust and custom ground turbo cams, If I had the money I would do that setup in a heart beat. What are you looking for exhaust wise? loud raspy? or deep rumble? for a 4v you cant beat bassani, hell even 2v bassani sounds amazing. I like the setup of the slp o/r x pipe and mac flowpath catback, sounds AMAZING on a mach 1

Full bassani
2004 Mach 1 - Bassani Exhaust

Slp X pipe + Mac Catback
2003 Mustang Mach 1
Stock manifolds
SLP off roa - Video

MRT H Pipe + SLP loudmouth
04 MACH 1 SLP LOUDMOUTH & MRT H-PIPE - Video

These are my favorite exhaust combos for mach 1's just thought I would throw those out there for you.

[The Abyss]

That is funny. When I heard that car my heart skipped a beat. Absolutely love the sound of it. I want a deep rumble. I want it loud so I was thinking SLP but I don't know if I should go X or H pipe and what kind of cats if any at all. I want to do headers too but I don't know about them either. I was thinking long tube JBA. Any thoughts?