The front brakes on a 2wd f150 are a one piece hub and rotor. You can either replace them with the original type or there is a kit available from Centric to convert to a 2 piece separate hub and rotor. Either one is pricey, but if you convert to a 2 piece it will be easier and less expensive in the future. Do a search for "2wd brakes " and there are discussions about this.