This pre-assembled differential is ready-to-install in any Magnum 272R^™ transmission. The sealed differential comes filled with grease for smooth hard-charging action. The differential will also accept silicone differential fluid which may be used to vary the limited-slip performance. Use ultra-thick 500k fluid for drag racing applications. Includes 10x15 mm bearings. Does not fit standard Magnum 272^™ transmission.