I have a ton of suggestions! I've done alot of what you've done and more; I assume you have a 1984 coupe (I have the same year)???
Install "energy suspension" mustang trans mounts in place of the stock mushy
engine mounts (or the 034 versions), then get rid of the snub completely! I haven't run one for 10 years!
Replace the trans mount with the 034 "density" version (not the super hard "Track" version) mount.
Lose the timing belt cover, front, back, all of it, oil cooler will protect it (you'll need access to the pulley)!
Get a MC2/5000T or NG/NF "90" cam and install it, more duration than the "KX" cam
Get an VW 8V adj. sprocket from Techtonics, you can play with the torque curve to suit your needs on track.
Move your oil cooler to directly in front of the cam pulley (see my pic), you'll get much better airflow, mount it "connector side down" so the oil will drain out when you do an oil change.
Get a 20v oil pan, you'll need all the baffling it has for the track!!
Make sure you have ALL the radiator ducting in place, seal up any holes, I still run the stock radiator on a 2.6L 20v with a seriously built big valve head, 276° cam and on alcohol (E85), I see 195° temps on fast tracks, oil is what gets hot on my car.
Mustang trans mounts:
Whole bunch more:
Do you have coilovers? hard to tell from the pics, you gotta run a rear bar (Addco makes one for the coupe), these cars understeer like pigs on the track!
You can bolt in a 4000q front bar and drop links: 26mm vs 22mm for the coupe. This will help roll quite a bit, but cause the car to understeer more!
You can shim the rear stub axles with "EZ shims" for more camber and 0 toe, you'll need and adj. panhard bar at some point, the rear axle will be slightly offset from lowering the rear....
The front needs much more work and is harder to do, it needs serious camber, you're lucky if you can get -1.5° with the stock setup.
The only real way is to convert to "90" 2 piece struts, you can then get camber bolts to create neg. camber at the "knuckle" (you can get as much as -3.5°), you will have to use the "90" outer cv's, redrill the hubs for 4x100 bolt pattern and machine the hubs "OD" (I just had this done and know of a guy locally who'll do it).
You can run Corrado 11" rotors and G60 2 piston calipers with this setup (I'm running Wilwoods).
Keep the crappy tires and thrash on them! Use them to determine what the balance is front to rear, your limits will be lower and slower, so you'll have time to figure out what's happening before you lose it on track!!
:cheers: 
