Just a short FYI, if your cars have dedion rear ends or a disc brake converted live axle, then you will need to install a bracket in/under the tunnel to hold the new outer cable so you can connect to the existing inner cable. The bracket needs to be pretty stiff as the tension in the cable due to the more mechanical advantage of the underdashe lever is pretty high.
i had to go through this for my disc braked live axle car, it is not pretty and it works after a fashion, but i wouldn't leave the car parked on a slope!!
Phil B (7 at last)