maybe in an oven if you can set the oven temp at about +25F over the limit...
although they may work when you test them, will they work everytime ?
The 155F & the 250F should have opened before the 325F had a chance to blow.
Also make sure your heater element didn't sag and get mid-shorted to ground, that would continue to heat after the thermostats shut off.
With dryer un-plugged:
Measure resistance from heater to ground.