I've been looking at some early (2003-2004) 6.0Ls with a little over 100K on the clock that don't show any signs of modifications-no stacks, gauges, tuner boxes, etc...most of them look like well cared for daily drivers that came in on trade for something newer. I am looking for a weekend vehicle that will see use hauling hay and materials and occasionally pulling a small animal (sheep, goats, etc...) trailer. No super heavy hauling, no tuners, no chips, no modifications, and it won't even be a daily driver. That said, assuming I buy a truck that was well cared for in the first place, do I really NEED to do any "bulletproofing?" Again, assuming I'm going to take good care of it and not beat on it, can I expect to get another 100K trouble free miles out of a truck that already has 100K under its belt? Knowing whether or not I'll need to budget for this stuff will really dial in my search for a truck, so any guidance anyone can give would be appreciated.