If you have no emissions or inspection then it's really up to you.
Having said that, back in the 70's & *early* 80's it used to be that you COULD pick up some HP & torque by removing the factory emissions features. HOWEVER, by the 90's & beyond with the advent of computer controls there really isn't an awful lot to be gained by getting rid of it. While you CAN swap over to a carb and get rid of everything you'll have to trash the computer and in doing so you're going to give up HP, torque, milage and drivability. On top of that you're going to have quite a bit of rewiring to do in order to make the whole thing run & drive unless you plan to just replace the harness with something from a carb'd truck but even then replacing the main harness is NOT an afternoon project. Late model trucks run very well with the factory fuel injection & emissions. The air pump is NOT a hydraulic pump and doesn't scavence very much HP from the engine so there isn't much to be gained by ditching it. Fact is that whatever you *gain* by removing the air-pump and emissions hardware will probably be more than offset by the efficency you lose by swapping to a carb and the net result will be a truck with worse milage and less drivability. 70's emission engines were one thing, by the time the 90's rolled around the SAE engineers had a pretty good handle on things.
Getting rid of everything WILL make the engine easier to work on and diagnose, but it'll cost you in milage & drivability.
