My buddies boss has an 04 6.0 that starts hard sometimes. It has had egr blocked off cooler and all, new injector wiring harness,O rings in the oil pump and a few other things done to it for the hard starting. Where he had it worked on they told him he needed an injection pump do the 6.0s have injection pumps? im not very familiar with them. If they do have one how hard is it to put one in? What else could be causing it to start hard? Thanks Justin