I have replaced mine on 1999 Eagle, but it was already a 2 piece. It also was a little different design than the OEM and appears to be more robust.
I don't know what the difference would be in the year models as far as the manifold goes, but have you looked in Cummins Quick Serve? I took my engine S/N to Cummins and had them look up current part #
It's not a horrible job to R&R it, but not the most pleasant......You could have just blown gaskets, and can take the manifold to a machine shop for resurfacing. Be sure to replace all mounting bolts, there prone to break (ouch) Spray PB Blaster all over them and turbo hardware for a few days before removing....
http://www.irv2.com/forums/f107/cumm...nt-290537.html