Starting problems 72 Mustang?

This is usually caused by a starter that's drawing too many amps. This would be a great time to make a very good and beneficial upgrade to the late model high torque starters (93 Mustang 5.0). The high torque starters are much smaller and spin the motor over much easier. The starter relay on the fender will need to be replaced and the battery cable to the new starter solenoid will need to be installed on the battery side of the relay. A new wire will need to be ran from the starter cable side of the relay down to the small terminal on the starter so that when the ignition is turned to start it will send power to starter solenoid and engage the starter. Good luck, hope this helps.