I am wanting to put disc brakes on my 72 blazer along with a locker and gears, so I have decided that it would be cheaper to swap out the axle with a newer axle with disc brakes. Either another 12-bolt or a 14-bolt, but it will need to be a 6 lug set-up. Should I look for a unit with a factory locker? How does a factory locker compare to an aftermarket locker? Will a gear set (4.56) be more expensive and harder to install? I would also like to get a axle that is closer in lenght to the front axle (67.5" WMS to WMS).