I have a 2002 F150. 4x4. I plan on getting a twin turbo 427 ford small block with noz. I have 3.31 gear ratio. with a 4.6 V8. And its slow, barley do 50 mph up a bridge. I plan on drag racing Camaros, vettz, and Silverados. And leaving them behind. Need to know the best rear end for my truck. what size tires and rims. should I kill the 4x4. Anything y'all have to offer!! Thank you P.S Remember we're built Ford Tough without tax dollars

 

3.31 are road gears. Not for acceleration. 3.73 gears will get quite a bit of acceleration... 4.10 gears will give even more. Depends on the top end you want and if your expecting any kind of decent MPG................ but with a 427, I don't think so.
Don't matter if you use the 16 or 17 inch tires. The overall diameter is approx. the same if the 16 have 75% side walls and the 17 inch have 70% side walls.

 

If you are truly going into that power range, none of the stock running gear will take it.
Your basically going to build a drag truck and everything you do has to be up to the torque in the lowest gear and the tires to lay that power down..
That means everything.
If not, the first time you put the power to it something will break and let you set.
A 427 big block will not bolt to any late trans past about 98 unless it is 460 larger truck transmission.
Then the gear ratio depends on the torque available, how high the motor is built to turn and what trans is used for it's gearing.
Your question is ok but the answer behind your project cannot be answered so easily from what you intend to do.
The whole project has to have some engineering thought and not just put parts together and hope for the best.
This is based on the info in your first post.
Good luck..