Compressor Housing Question

[RBurroughs]

I have a quick question. Im purchasing a turbo and have the following choices for inlet and outlets for the compressor housing.
2-5/8" Inlet and 1-3/4" Outlet
3" Inlet and 2" Outlet
4" Inlet and 2.5

Theres about a hundred dollar difference between each choice. If this is just inlet and outlet, then it wont change the maximum hp output right? Just allow quicker spool-up? Or is it the smaller it is, the quicker it spools but less maximum hp capabilities?
Thanks in advance, once again,
Ryan

 

[turbolarry]

Match it as best you can to your injen intake and IC piping. You would always want the best flowing one, but unless your going to change all your piping, go for ease of installation.