The basic Zetec powerplant came from the early 2000 Ford Focus ZX3. The General Competition Rules of the SCCA specified allowable block numbers. These were RFYS4G6015AA, RFYS4G6015AD or RFYS4G6015AE. Cylinder Head numbers were also specified. These were RFYS4E6090AC or RFYS4E6090D. The Car-Part website revealed hundreds of used zetec motors in junkyards around the country, many within easy driving distance of my home in Northern California. Pacific Auto Salvage near the Napa airport had one such motor. The head and block numbers were on the GCR list, I paid $431 (including tax) and brought the motor home to begin the project.