Most disc brake kits are direct bolt ons. Even things like 13" rotors or the Wilwood and Viper kits all bolt on. There are even a number of rear disc kits that bolt together. Even if you are changing the original disc or doing a drum conversion, all the parts bolt on. If you have disc brake currently and want to upgrade to 11.75" or 13" kits, they still bolt on. Even the racing style aluminum hub kits with seperate rotors all bolt on.