my 1996 mustang gt

[The Deuce]

Aside from the fact that was a fairly presumtious opening post...

A turbo (or supercharger) will make a faster 96 GT than all the standard 'bolt ons'.

You want to have the fastest street automatic GT? How much $ do you have.

2500 Stall Converter
4.30 gears.
eaton rear end
31 spline axles
Fox lake stage III heads,
SHM Stroker shortblock
JE pistons, 11:1 comp
Big (and I mean Big) cam
Long Tube Headers/ X-pipe, flow through mufflers.
42lb injectors
255 lph fuel pump.
shift kit (I hate auto's so you're on your own here)
Polished SVT (bullit) intake
Chip (obviously)

That's just a start. You're looking to spend at least 10k, if you do all the install work yourself. I don't know what you really mean by "I repeat on the street, not on the track." That car described above would drive on the street, though some people might not want it as a daily driver. If you want to go 10's, and not lose any streetability, you're smoking crack. Then again, 10's wouldn't gaurantee fastest street stang, either.