The three early PACE plants sold to CFE (PACE 260 at Palacio Gomez and PACE 520 at Dos Bocas) involved an order for six (6) W501B gas turbines and represented the largest order placed by CFE up to that time. The story has it that the order was received on a Good Friday (ca. 1973?) after a very contentious competition with another major US supplier who used some rather "creative" ways to enhance plant performance. Everyone involved in the negotiation was anxious to get home for Easter, but not so anxious that they left before getting the order. The final plant on the list was built for CFE at Tula, Mexico, as a phased-construction project, where the four (4) W501D "EconoPac" units were shipped and installed on an ASAP basis,in simple cycle mode, to meet an energy emergency during 1979-1981. The HRSGs and steam turbine portion of each plant was added later and the exhaust stacks were removed. (Photo below is of artist's concept of converted plant. The four W501D "EonoPacs" were already in place at time of photo".)"