06 and 07'sn are great but these are the years that had internal pump exploding problems with the LBZ that took out all the injectors and contaminated the fuel system.
The trans lines leak in all climates.
Stick with what ya got, Injectors are the only thing to worry about and you can get a complete set with all gaskets for around 13 to 15 hundo and put them in yourself in a weekend if your not wheel chair bound.
This would be the TSB your talking about Rob
http://www.duramaxdiesels.com/forum/showthread.php?p=244806#post244806