Drake Whitehaed

SO my 95 k2500 is surging bad still after replacing the tps, sparkplugs, map sensor, cts, distributor cap and rotor, break booster, vacuum lines and the fuel filter and its still surging and stumbling. I don't know if it could be the iac valve but I'm gonna bet its not that either, the only things i can think to do now is look at the injectors even though they look fine and aren't dripping or spraying weird, and the fuel pump and maybe the fuel pressure regulator. when its idling its super choppy and when I come to a stop or shift into reverse it either will get super close to stalling or it will stall. The timing is correct even though it is advanced and that's because, if you put the truck in bypass mode the timing should be at zero which it is and if it isn't your supposed to turn the distributor which I didn't have to do. So I know its running way too rich. it seems no matter what I replace nothing wants to clear up this surging so if anyone knows anything that could help please say something at this point I'm open to anything that sounds like it might work. And if any thing i said about the timing is something you've heard is false please tell me.