I have a 99 Ford f350 with a 7.3 and when I'm accelerating my truck starts bucking and surging around 2500 rpms?

Black smoke dumps out and I lose lots of power. I have had several mechanics look at it and nobody has figured it out. I have changed the ebps tube, ipr, icm, one injector, injector o rings, valve cover gaskets, cps and some other stuff. Could it simply be something with the turbo? Feel free to put in your $.02, any help will be appreciated. I have a stock tune it it now, when I put it in tow or extreme, it happens quicker.

Black smoke on a diesel means too much fuel, or too little air for the amount of fuel.
(Blue smoke means it's burning oil somehow).

I'm not familiar with that engine, but I'd check the air intake system and the turbo controls; if the turbo has a bypass control or variable pitch control - an actuator fitted to the turbo body - check that is operating.
It's also possible for the actuator to move but a variable pitch still be jammed inside the turbo, so the turbo is not giving the engine enough air for fuel to be burnt.

Whilst you have that problem, keep an eye on the oil - a lot of unburn fuel can cause leakage around the rings and start to dilute the oil, if any liquid is left in the cylinders.
If the level increases, you have oil contamination.
If that happens and is allowed to continue you can end up with bearing damage or a runaway engine.

Edit - there's a dedicated Powerstroke forum here:

Lots of posts about black smoke problems on the 7.3 engine.
From a quick look, check the turbo "waste gate" operation - if that's stuck open you will be losing boost so insufficient air.

These "several mechanics" you have asked to look at it… How many of them are trained as DIESEL engine mechanics? Maybe that should be your next stop… Find someone who actually knows what they are doing to work on your truck.

Check trouble codes with a scan tool. It is very likely a bad HPOP, common failure on these Powerstrokes.