As mentioned above Fore fuel system, solid set of injectors (I am partial to the Injector Dynamics brand), McLeod RXT, 26 spline input shaft, full FTBR kit, and a heat exchanger. IF there is any budget left over consider adding some stopping power to the car.
I bought a set of aftermarket ones a while back to have as a back up option but I am about to dig in and hunt for a set of OEM NOS ones or a really good set of junkyard ones.
Out of left field question here. Are the fender liners specific to the '03 '04 Cobra or does any 99 to '04 Mustang fenderliner work? I'm hoping to find a set in really good condition or a NOS set for my project.
I have the entire Stifflers catalog with 1 7/8" x 3" collector long tubes. Everything fits. If you want to see how it looks and fits my build thread is below.
https://www.svtperformance.com/threads/the-1-of-23-sonic-blue-w-parchment-build.1199240/
With your setup the easiest path forward would be going the Bilstein B8 route and letting it ride. Maybe some while you are in there items like bushings.
I forgot to make a small update in January before I left Arkansas to go back to Vegas. My buddy and I swapped out the old janky pillar pod and gauge setup (not sure on brand). I have been holding onto a Speed of Sound dual gauge pillar and two Aero Force gauges with the SVT faces.
One this is...
Depends on how wild you want to go. If you want good then solid rack bushings, offset front control arm bushings. Bilstein HDs, H&R race springs, weld in subframe connectors, Steeda sway bar & sway bar end links. If you want wild & have deep pockets then tubular k member, tubular control arms...
Upgrading the stock brakes is a good option. The first brake upgrade I did was StopTech slotted cryo rotors, Hawk HPS pads, Motul RBF660 fluid and Russell SS lines. It was a good setup and did well on the street for everyday driving. Also provided that emergency stopping power if required. I did...
Oh I have 100% ruined a 1 of 23 car.
I do not think there are many people who appreciate the direction and result of this car. It's the major catalyst for why I often choose not to sell.
Also way to burn yourself haha