For those who haven't read my thread in the 2nd gen side my truck burned up in our shop fire today. So I'm truck shopping but feel pretty unsure of myself since I wasn't planning on truck shopping for a lot of years! For starters a quick search found me a 2008 2500, 6.7 with egr delete, 6 sp manual, reg cab 8 ft box, 165600 km, $23500. What things should I be looking for in this age of truck? I'm totally new to 3rd gen and common rail cummins and manual trannys. 

then 3rd gens need better filtration. the 6.7 however i think had better.
do the normal blow buy test on a warm engine.

for the 5.9 03-07.5 you'll want to check the HVAC doors. the door switches usually stop working as the wires between the doors and jamb brake. the usual balljoints. 

thanks all i can offer.

me personally i'd stay away from a modified truck. i buy STOCK!