03 6.0 surging idle stalls and occasionally wants to take off on its own

[Roll n Coal]

okay here is the story,
I have an 03 6.0. Lots of new parts( Head gaskets, hpop, oil cooler,everything in the hp oil system,turbo,engine wiring harness, ficm,8 new pistons rings and bearings,new egr valve,egr cooler, 3 new injectors), and a few other misc items. The truck starts and runs fine, then it starts to idle rough and surges between idle and 1000 rpm. sometimes at red lights i have to keep both feet on the brake because the truck will try to accelerate on its own. Then sometimes when coming to a stop it will stall out. After stalling it always seems to restart. i have also noticed that the truck feels like it has a slight misfire around 3000 rpm. All of these problems started before any parts were replaced. over the winter the truck spent almost 2 months at the dealer and they still cant figure it out. If anyone has any input as to what could be the problem it would be of great help.