Brakes
You should try some NAPA Premium pads. The ones you want were what they called their Ralock pads. I don't know what they call them now, but I use them on my ITC Renault and no one can out brake me with their high dollar pads. The cost is between $40 and $50 a set.
You have to bed them. They will give you a hard pedal about the third lap, then after that they don't fade. If you need it I can get you the numbers off my pad box and maybe they can identify the type for you. I am pretty sure that they would make them for your Mustang if they make them for a Renault! I used them on my IT-B Pinto for years. They worked great! And cheap!