Original equipment on 2017-2018 Mustang GT350 5.2L, these Variable Cam Timing (VCT) phasers require proper oil pressure to function correctly. It is inherent that all cam phasers have a certain oil leak rate. These high-performance cam phasers have a much lower leak rate than stock, allowing better control of the phasers at higher engine speeds and loads. These cam phasers are oriented for racing applications.