heavy haul truck, that don't like heavy hauls!

[un_yun]

First off let me say thanks to Rawze and everyone else out there for trying to help guys like me. Now down to business. I have an 06 cm870. I do heavy haul, but not super heavy.(132000 max) I have done all the stupid stuff you shouldn't do before I became aware of the library of knowledge here. I still have the mandate, but I did have international bump it up from 475 to 550. I did notice a little better driveability. seemed like a little flatter torque curve. I wonder if the put the right file in though. so I had cummins chk it, they said all was good. While there they replaced my pig tail going to my valve and dyno'd the truck. They said it was putting out 445, and that was with in spec's. So I paid and then left.(couldn't tell much difference). So I purchased a inj leak tool, and well #5 was bad. Replaced it, and maybe a little difference could be felt. I had a bad vibration at high boost. I cleaned the imap and that helped a lot! I said all that, to say this. I am still not sure it is running like it should be. I live in S.C. whom should I consult that you guys trust. I can't find anyone. Oh and my fuel mileage is in the turlet. Like 3.88, I now I am never gonna see the numbers you guys see, but 5 would be great.