Our Valve Retainer Upgrade Kit increases the reliability of your engine by reducing the possibility of valve float at high rpm. Includes 16 lightweight, precision-machined titanium valve retainers. A must for IJSBA & APBA Stock Class race craft./p> Note: For modified engines (Stage 3 & above) we recommend the complete RIVA Valve Train Upgrade Kit (part # RY19040-VTU).