Nuclear Magnetic Resonance (NMR) Spectroscopy is an important technique to obtain structural information of a protein. In this technique, an essential step is the backbone resonance assignment and Structure Based Assignment (SBA) aims to solve this problem with the help of a template structure. Nuclear Vector Replacement (NVR) is an NMR protein SBA program, that takes as input 15 N and H N chemical shifts and unambiguous NOEs, as well as RDCs, HD-exchange and TOCSY data. NVR does not utilize 13 C chemical shifts although this data is widely available for many proteins. In addition, NVR is a proof-of-principle approach and has been run with specific and manually set parameters for some proteins. NA-NVR-ACO [M. Akhmedov, B. C ¸atay and M.S. Apaydın, J. Bioinform. Comput. Biol. 13 (2015) 1550020.] remedies this problem for the NOE data and standardizes NOE usage, while using an ant colony optimization based algorithm. In this paper, we standardize NA-NVR-ACO's scoring function by using the same parameters for all the proteins and incorporating 13 Cα chemical shifts. We also use a larger protein database and state-of-the-art chemical shift prediction tools, SHIFTX2 [B.