When sourcing Garrett turbochargers, the most critical step is verifying the unique serial number and part number etched on the identification plate. Genuine units feature high-precision cast compressor wheels and Inconel turbine wheels designed to withstand temperatures exceeding 1,000°C. Buyers must ensure the turbo matches the specific engine displacement, horsepower targets, and flange types (e.g., T25, T3, V-Band). For performance applications, prioritize models with Dual Ceramic Ball Bearing technology for faster spool-up and increased durability compared to traditional journal bearings.