If you're talking the main engine harness, you're pretty much stuck with one from an early 99.
94-97 PSD's had TWO connections to each valve cover gasket instead of one each.
99.5 and up have the Intake Air Heater that the early 99's didn't
There are also different flavors within years, depending on whether it has dual alts, AC or not, etc.
If you have a bum connector, those can be repaired with a little splicing.