I suggest you cancel the order. 75mm is for blown applications. 70mm is plenty, and still causes a slight loss in low end torque because of it's larger diameter causing reduced air velocity. I have the BBK 70mm throttle body, and to be honest, I wish I got the Ford Racing 70mm TB. The BBK one sticks when at closed throttle so when I try to give it just a bit of gas, I have to press it harder to get it unstuck and then it goes over where I want it. When driving in snow, this is very annoying when trying to keep some traction.
I suggest you start with the exhaust. That was my very first mod and made an improvement. Try to find a place that will custom bend a full cat-back H-pipe system for you. H-pipe sound better and improve low end torque which is what these cars really need. 2.25" mandrel bent pipes are the best for these cars mostly stock or lightly modified.
And gears will be one mod that will speed you up the quickest. You have 2.73 gears like I have. My dad's 99' CV with the Handling & Performance Package (HPP) has a faster takeoff because he has 3.27 gears. Those are what come standard on most year Police Interceptors. I'm going to Summit today to get a set of 3.55s for even more of an improvement. This does affect highway mileage, though. So be know what you're getting into. And if you want both wheels to put the power down instead of on wheel spin and the other sit there doing nothing, get a Trac-Loc. I got a used one out of a Mustang for $50 and got the carbon fiber rebuild kit which is used on the Cobra from Summit. You can go with regular clutches but they do not last as long for around $30 less.
Oh and PI does not mean Police Interceptor. CVPI means Crown Vic Police Interceptor. PI means Performance Improved. In 2001, the Panther platform got the PI engines which has improved heads, intake manifold, and exhaust manifold to increase horsepower by 20HP. You can take the engine out of a 2001+ car and drop it into your car without changing any wiring. You will have to use your original fuel injectors as different years have different sizes and connector types. For best results, a computer tune is recommended to optimize the performance from the new engine. Other people just swap on the PI heads manifolds, and cams. This leads to a compression bump because the NPI (Non-PI) pistons are not dished and the heads have a larger combustion chamber. PI pistons are dished and have a smaller combustion chamber. Putting the smaller combustion chamber on an NPI block with the non-dished pistons results in the compression bump and slightly more power at the cost of having to run higher octane fuel to prevent knocking.
In the mean time, you can do a few mods for cheap in your garage. There's the bumper tuck (aesthetic), the J-mod, and the headlight relay harness (makes a huge difference in how bright your headlights are).