I own a 95 Montero LS 3.0 with limited slip, would like to install locking differential in rear axle. I've located a locker out of a 98 SR gear ratio 4.63 with 51 ring and 11 pinion. I'm told my 95 gear ratio is 4.63 as well, wondering if this is interchangeable? Are the gears the same size? Will the axles match up with the 98? If so do I need a onboard air comp installed or is this vacuum activated?