You don't need anything else rear cradle wise. Simply unbolt the driveshaft from the giubo (coupler). Early SRT uses a 4 bolt flange; Getrag only uses 3. You can either source the back of an R/T driveshaft or just get a whole new one for a '12-'14 SRT Charger. If you don't have one you will need the correct 392 giubo to connect to the Getrag properly.