Cessna 310i (eye) Powerplant and Cowling

Hello, I work for an aviation maintenance school and we have a Cessna 310I (eye) which is without engines. We are looking at purchasing two powerplants for the aircraft. The standard powerplant for that model is the IO-470-U. My question is whether any other IO-470 model would work without any cowl modification. Alternatively, does anyone know of a Cessna 310 guru or organization I might ask? Thanks very much!