2001 mustang gt overheating
My car overheats above 50mph it has a slight radiator leak
but I'm concerned about it getting hot I just changed the
thermostat and no luck any ideas?
A faulty thermostat can come out of the box brand new. You could get a lower temp thermostat for that model with a lower temp threshold for opening. With the leak though you may want to repair that first because leaks alone can cause over heating.
Replace the radiator!