capnjim, this is just my personal preference but I would recommend all of it. Or at least as much as possible. Which would save you from digging down into the front of the motor over and over. The accessory drive system of a 6.0 is kind of like a timing belt in an OHV motor. Just plan on changing everything after 100K mi or 9 yrs.
If you have the means my preference would be to add these to your list.
- Just change all the Idlers (at 90K mi mine were like old skateboard wheels)
- The complete belt tensioner not just it's idler.
- Vacuum pump if it's original. (it will be staring right at you, not that expensive, easy to change)
- Coolant/Heater hoses if original or chafed. Mainly the one that goes down from the degas bottle. (it will be right there and easy).
- Power Steering Pump if your really ambitious ( Kind of a pain and a little early at 100k mi but again it's right there at that point)
I've done all this on mine and in several tear downs unfortunately. At least on mine the biggest pain is removing the fan/rear shroud assembly. Take your time with that part.
2005 SMB RB 4x4 6.0 PSD
A rocket on the pad is safe,
but it's not what rockets are built for.