Give dp Tuner a call and tell Jody what you want the truck to do, he'll hook you up. Eliminate the EGR, that is what gives the 6.0 the most problems because of the heat. Put a good exhaust system on it from front to back, and uncork the intake with a good cold air package.
The 6.0s biggest weakness is the 4 bolts per cylinder holding the heads down. The 7.3 PSD had 5 bolts and don't pop the gaskets unless you do something stupid. The fix is to get a set of ARP studs and get them installed, once that's done you don't have any more issues.
Any thing that can be done to help manage the heat better in these engines will make them last longer. Elite Diesel plays with these things all the time and there are articles in Diesel Power that you must read so you can get an understanding about these engines.
I am an advocate of Evans Coolant, if for no other reason than it will make the engine more reliable and thermally stable. No additives needed, super high boiling point, lasts for 10 years, evens out the temps in the block and heads so that things stay together.
