Can any of you tell me witch one I need for my setup please . I'm running a 4x4 setup in a focus with a skyline gear box the diff,s are 3.6 at the mo that are in the car but I'm happy to sort a front if I need to go to 3.9 any photos and info of witch one to get and any info ware to get one from would be grate thanks for your time . Ian