migration of nt

v want to migrate our nt domain to 2000 or 2003 domain.v have 1pdc,1bdc and a 2 node cluster (nt member server) in which some application will work only in nt.my question is can i upgrade nt domain controller to 2000/03 domain by keeping nt cluster server as it is.will nt cluster server coexist with 2000 or 2003 domain