Not sure about the Turbo spooling up correctly. I don't have a boost gauge but pulling off the boost line from the intake to the waste gate actuator at idle there is positive pressure. I wouldn't think that at very low RPMS the turbo would be a big part because it hasn't started spooling, maybe I'm wrong though. If I pull the intake hose and can spin the turbo with my fingers is that a good enough check for the bearings being free? What cost am I looking at for a rebuild if I need one?

Truck rolls fine so I don't believe that its a mechanical issue with brakes etc. I've checked timing the timing, I'm missing the cam timing mark on the aluminum plate it has been broken off since I've owned the truck, but I can made a pretty good guess by looking at my friends truck. (the pin on the cam is at 12 o-clock right. Any chance that the 4d56 heads have a different timing mark than the 55?

Latest check reveals that cracking injector lines one at a time #3 cylinder makes very little difference in idle speed. All the others nearly kill the rig. I'm getting good fuel spit from the line so I'm thinking maybe a dead cylinder. Valves or rings. I'm going to do a comp test and leak down test next and go from there.

About the head it bolts right on no issues. A friend of mine who has a shop out in Oregon ordered the head for me. I'm not sure what his source is. I've heard you can get them on e-bay but also heard poor reviews of the Chinese heads.