The 900HP Level 5 kit for the 1992-2001 Impreza STi (GC8) and 2002-2007 Impreza WRX (GD) with STi R180 Rear Differential Conversion is a complete rear system including both drive-shafts, hubs and ARP extended studs. The drive-shafts feature aerospace grade torsional 32 spline axle bars, increased from the factory 29 spline bars, and a billet ball & cage inner CV with a high grade inner differential spline for the R180 differential, and a "Driveshaft Shop" one of a kind outer CV with a larger spline. The hubs are made to accommodate the larger spline and are also able to accept the factory ABS ring.