I had a patient yesterday with an 06' with 765000. He bought it new. 2wd, stick, drw. Lifelong ford guy, well not anymore.lol. He said aside from normal wear stuff he's done a water pump, he thought a tps and a piece of the engine harness. Nothing internal, and still pulls daily with it.

Don't downplay reman injectors either. I have put many in duramax's, N14. 3406, 7.3's etc... They are not done by some joe blow at his kitchen table. Many come with warranties and I've never had to pull one I've put in. Some guys just weigh the cost vs benefit of new for their application.

You can also run an oil sample on it. See if your making oil etc. that's always good knowledge to have. Good luck.