summary

1) Brahma provided the Harekrishna, Harerama mahamantra for us as a means to praise Narayana
2) The names Narayana and Krishna are interchangeable
3) Narayana does not show four qualities
4) Krishna is the original god

Any reference any one can provide if Rama also does not show any qualities and the names Narayana and Rama are interchangeable