Whats needed for a SN-95 5.0 to go 13's?

[91LX2Bfast]

I am looking to buy another Mustang soon, and I need to know what it would take for a 94-95 GT 5spd to run consistant high 13's.
I used to own a '91 LX 5.0 5spd and I know that they were pretty easy to get 13's.
I am comparing 90-92's and 94-95's. Since I already had a Fox, I would prefer to go w/ the SN-95, but if I am going to have a tough time holding off my friend's imports, I will buy a Fox.
Can I go 13's w/o slicks and w/o getting into the heads and cam? What would something like gears, full exhaust, intake manifold, TB, MAF, and shifter pull?
Or should I do a PI head swap, TC, and gears and drive a high 13 sec sleeper Tbird?
I'll welcome your opinions?

------------------
1997 Thunderbird 4.6L: Dynomax cat-back, MN-12 perf. offroad downtubes and Y-pipe w/ Magnaflow resonator, 80mm MAF with cone filter, B&M trans cooler, Inject-Tech chip, MAC U/D pulleys, KVR front brake upgrade, SVO 70mm TB. 15.2 @ 91 w/ just chip and MAF. 14's next time to the track.

No Longer own: 91 LX 5.0L 5 spd