1992 Mustang rear disc brake help, ebrake causing a binding

hi im new to mustangs and just brought a 1992 5.0 lx. which has had a rear disc brake conversion, The parking brake has been disconected because when its connected the brakes bind has anyone else had problems like this when they have uprated there brakes ? im not sure if the Parking Brake Cables have been uprated i havent had a chance to check gona have it apart next weekend any help would be appreciated