E-Brake
1) The park brake lever is a self adjust. There is a spring on the side of the lever that automatically adjusts the cable tension. Make sure that is still OK and putting load on the cable.
2) Check the clearance of your park brake shoes. The park brake is a drum-in-hat design. On the f-bodues we have a mini drum brake inside the rear rotors for the park brake. You can adjust the park brake shoes but need to remove the rear rotors to do so (if I remember correctly). I don't think there is an adjuster access on the backing plate. If there is, you can adjust it through there. Adjust the park brake out until you get a little drag on the rear wheel and then back it off a little. You do not want brake drag due to the park brake.
If both conditions are satisfied you should have a decent feeling park brake. These cars generally have a bunch of travel to apply the park brake and have the rear brakes hold the car. But it should not feel too soft unless you are stronger than most.

