As I see it the oil, fuel ,and air filters are all different from 1998.5 24 valve and the new 2006 cummins . Right or wrong.

 

Oil and fuel for sure are different, not sure about air filter.

 

The fuel filters are different from '97 thru '99....they are the same from '00 thru '06. Any 24V oil filter will work; it's just the '03's and up have the fluted end for a oil filter wrench. The air filters are indeed of a different design.
Greg

 

Looks to me like the oil filter is smaller around on the 06 then the 98.5.??