Answer:
Whipping cream is almost the same as heavy cream but is a bit lighter. I have used both interchangeably in many recipes without problem.
One thing I would suggest is to use a prob thermometer in the quiche. It is a good idea to have one around anyway for all kinds of things. Set the alarm to go off at 165°F. This will allow to bake the quiche to the perfect temperature for the ingredients you use.
A setting of 165 is the very low end for a quiche but remember, the quiche will keep cooking after it is removed from the oven. expect at least another 5°F rise in temp after you take it out of the oven.