So I've done a bunch of research on the subject of a 6.4 of the dos and donts and all that but I do have a question that I can't seem to decide what to do. I'm looking at one with 78k on it that was deleted at 50k and it has a spartan tuner on it. I've read of a lot of people using them but my buddy that is a ford mechanic said to stay away from it. What's your opinions?

 

In all the research I've done the general consensus is no. Look up Powerstrokehelp on Youtube, he's a mechanic who specializes on Powerstroke engines and has a lot of great information on Youtube.

 

The problem is that engines that have overly aggressive tuning on them are often time bombs. Red-Ford is right, check out Powersrokehelp.org and watch some of his informative videos. Essentially you can bullet proof a 6.0L or 6.4L engine and have it last, but the chances of a failure on a heavily tuned used truck are going to be quite high, or at least that's the impression I keep getting.