Technical Excellence Center for Car Maintenance Engine and Gear Overhaul, Servicing We have refurbished Datsun engines with a warranty, ready for installation, for old and new models from 1980 to 2000. Refurbished old GM engines available: 450-350 -305. All engines are refurbished and come with a warranty. New and used spare parts are available. We work on gasoline and diesel GMC vehicles. Technical Excellence for Car Maintenance.