We have measured the kinetic energy release distributions for unimolecular C-2 loss from singly and multiply charged SC3N@C-78(z+) (Z = 1, 2) and SC3N@C-80(z+) (z = 1, 2, 3). Using finite heat bath theory, we deduce the dissociation energies of these endohedral ions toward loss Of C-2. The data show that the complexation energies (i.e., the adiabatic binding energies between Sc3N and the fullerene cage C-n(z+)) are, for a given charge state and within the experimental uncertainty, identical for n = 76, 78, and 80.