Interesting, in that all the Kalitta/Kitty Hawk DC-8s were pax conversions. The S/N's are not telling me much - N811CK and N815CK were the only DC8-63's in that fleet -the rest were 50 series and -61's, although they did operate 4 DC8-63's for Bax Global, which were leased/owned by Bax. One of those, N867BX, was purpose built as a freighter - rest were pax conversions, all ex Air Canada