hopefully it's not the head gaskets, but at that mileage it sounds ohhhhh too
familiar.  it could be some other things like the pump, or hoses going to and
from it, check everything first before you assume it to be the head gaskets,
as that is the most expensive fix-it job for a leak usually.  if it is a head
gasket problem, then there are a lot of good things to replace and fix while
your back side is dissasembled.  write this list back for a complete list to
take care of while your getting new head gaskets....if this is the case.
good luck, jeff

ps, you can still drive around awhile with a gasket leak, just eventually it
gets worse and will NEED to be fixed..