The three alterations discussed in this report have an effect on the parameters used in Total Control Calculations for C Reactor: Conversion to smaller diameter and shorter vertical safety rods in six outer control channels; installation of forty-four overbored tubes with short fuel charges in the flat zone and an associated increase in spike enrichment; and centralization of the enrichment ring into a three-lattice unit width in place of three and one-half lattice units previously in use. New parameters are derived in this document for future total control calculations.