RTS ring and pinion sets and Mini Sppol Kit, manufactured to meet and exceed OEM specifications that is required for todays modern performance car.r. The design, tooling, steel selection, and heat-treat recipes are all controlled by the RTS Manufacturing factory to produce cost-alternative ring and pinion sets. RTS ring and pinion sets offer exceptional value with better-than-OEM quality. Available in a wide variety of gear ratios for your Modern Holden Commodore or Ford Falcon with M78 Differentials .